Ever have a time when you told a friend or a professional something and they just dismissed it out of hand? It probably did not make you feel very good. It probably did not inspire a lot of confidence that they knew what they were talking about. If they did not bother to consider what you are saying, to look into the matter, how are they dismissing your claims without any counter evidence? Think about it from that perspective the next time a client or potential client is telling you a story that sounds far-fetched. If you are a private investigator, a research or intelligence analyst, or a security professional, you have probably heard some tales that sound right out of the Twilight Zone and thought to yourself, "This person needs a straight jacket." But before you write them off, think about that time or times you experienced something that you just don't think people would believe. I feel like too often I see professionals want to write these people off and immediately suggest they get mental health without bothering to look into the matter.
I encourage anyone that does investigations, analysis, or academic research to read the The Report on Unidentified Flying Objects by Edward J. Ruppelt (CPT, USAF, ret). Captain Ruppelt was assigned to the famous USAF Air Force investigation known as Project Blue Book alongside the famous astrophysicist Dr. J. Allen Hynek. These two men took a serious and professional tone to this investigation despite the ridicule they received from those who thought the whole thing was ridiculous. They did not try to prove or disprove the existence of extraterrestrials. They simply investigated sightings and tried to determine reasonable explanations for the cause. When they could not determine a reasonable explanation for the cause they marked the investigations as unknown. While the term UFO has become a word that a lot of people use synonymously with alien that was not the intent of Captain Ruppelt when he coined it. It simply meant exactly what it is, a flying object that is not identified.
Whether you are hired to investigate the seriousness of a received death threat or the existence of the Tooth Fairy you should bring the same level of professionalism to the task. Your job as an investigator is not to prove something is real or not real. Your job is to investigate and bring available facts and observations to package the investigative findings into a final product for your client whether the outcome pleases or displeases them.
Is there an ethical way to accept assignments such as a client believing the government is surveilling them, that their house is haunted, or that they saw an alien spaceship? Absolutely. The first scenario is the easiest one. Use basic surveillance detection and TSCM to try to determine if anyone is spying on them. Maybe they really are being spied on but perhaps it's the pervert down the street or that kid that just got a new drone and is snooping around the neighborhood. Or perhaps you do not find any evidence of surveillance and have to provide those findings as well.
But how about something like that alien spaceship sighting? Certainly that one has to be more tricky right? Not really. Basically, you use the scientific methods that Dr. Hynek and Captain Ruppelt used such as first determining if there were aircraft in the sky at the time, checking with meteorological stations to determine if there were meteor showers or other weather phenomena picked up by radar. At the end of the investigation you will have one of three things. The first is a high probability that the person saw a known object that was in that section of the sky at that time such as you were able to find out a plane crossed the sky, or a comet, or a specific satellite or a range of satellites that would have been visible at that time. The next is a list of possibilities such as a meteor, falling debris, an unknown that possibly could have been seen at that time. The last is an anomaly. There is no reasonable explanation for what the person saw. It was too overcast to be one of the possibilities such as meteors or satellites, and no known aircraft were in the area. No matter how much they want to believe it was aliens we can't say "well it must be aliens." If we do our jobs diligently and none of the possibilities pan out the best we can provide them with is that we have an unknown and we can show them the list of what has been ruled out and why. When it comes to having something that's a true unknown the important part is to show your work and how you discounted out all the possibilities that people will try to say it must be.
In the same way if your client thinks their house is haunted it doesn't matter how much Fox Mulder "I want to believe" you personally have or how much Dana Scully skeptic you have we still follow the Columbo model of just the facts. Whether or not such things as demons, angels, ghosts, and other faerie creatures exist is for the religions and scientists to argue about. As an investigator our job is to make observations, record evidence, and deliver investigative findings. Perhaps they are hearing strange noises. Perform a sound audit. Maybe you can track it down to a squeaky pipe or the way noise is carried by the vent system. Maybe they need an exterminator. They are feeling cold spots. Perform an energy audit same as their utility company would. Or just recommend that they have their utility company do it. If they are seeing things, then use basic surveillance techniques to see if you and your cameras observe the same thing. It may take some outside assistance of electricians, plumbers, exterminators, others that can find a probable cause or eliminate a potential cause from the list of possibilities.
At the end you have to deliver your investigative findings. Perhaps you found the cause. Turns out the noise was made by the leaky pipe. Perhaps instead of an angry ghost throwing books off the shelves it was slight vibrations caused when the nearby train went by slightly shaking the wall. Or perhaps you don't find the cause. Perhaps you have eliminated every possibility which you came up with as a potential cause for their experience. It always sucks to be left with an unknown but an unknown with your available work is a starting point for someone else if they want to investigate further. The Catholic Church for instance requires quite a bit of investigation on some matters before they will step in. A professionally done investigation with sound evidence collection practices, documented, with corroboration, could complete their requirements for groundwork for them to say they will look into it to see if it is one of the matters that they deal with outside of the sciences. It may be the basis for which someone in the scientific community gets involved, seeing that you have done work of a scientific rigor which has led to an interesting anomaly worth their professional study.
What if you come up with a plausible natural explanation? Don't just assume the client is a wackjob and will be unhappy. Some people that have some very far out-there paranoias can be persuaded when set down and go over your findings and the work you did to reach your conclusions. Some people in fact may be very elated to have a reasonable explanation. Not everyone who thinks something may be paranormal want it to be.
What if you come up with nothing or the client is unhappy that you have come up with some plausible explanations despite them wanting a paranormal explanation? We know in a lot more standard cases that we sometimes have clients that will not be happy with our findings. This is not different. Retainers are always important in any case and should be here too. So is that clause they must initial reminding them that payment is not subject to you supporting their theory, but in delivering you findings and based on your time and use of resources and working within the scope of the contract.
Secondly, if you think it is appropriate to tell them to consider talking to a mental health professional you are now likely to get more consideration for your view. After all, you have taken the time to investigate the matter rather than dismiss them out of hand. You have evidence, whether it be recordings showing that nothing they claim to see is showing up as well as your own experiences that you observed nothing they claimed to have seen or experienced. For some people that will count for something. If they do not want to listen to you well you have done your best and it is time to end your investigation.
At the end of the day this is a business and we are here to make money. Ethically, there are right and wrong ways to do that. If you are out there using psuedo-science trying to prove an unproveable or support the client's claim, that's wrong. But if you stick to your Columbo mantra of "just the facts" and you use sound investigative practices you are doing it right. If you are up front with your client about the fact that at best your findings may find an anomaly that you cannot explain, but that it cannot prove the existence of paranormal entities then you are acting in ethical manner.