There is nothing more associated with the paranormal than a ghost story. The general eye-witnesses to a haunting can describe seeing, hearing, smelling and being touched by something unknown. Most of the evidence of hauntings only come from self-report measures (as they can’t be predicted) and occasionally a ghost hunting team.
The most logical place to start in investigating hauntings is whether the recently bereaved feel the presence of the recently deceased. In a few surveys, around a third of people reported a feeling of the presence of a deceased loved one, including being observed, hearing voices and seeing dead relatives/friends. A minority of people feel the presence of a loved one.
I have read and heard of thousands of haunting cases. I’m in no doubt that most people feel they witness a haunting and aren’t making it up. So, how do we best explain hauntings? There are two general explanations; (1) human misinterpretation and (2) genuine paranormal phenomena. The human misinterpretation can range from brain illusions (putting 1+1 together and coming up with 3) to misinterpreting something natural for paranormal, i.e., the creek of the floorboards. The list could go on for a while, but this is the type of phenomena.
The second explanation is a genuine paranormal phenomenon where no rational reason can be found. To get to this point, researchers need to rule out all other causes, which leaves us with only the paranormal explanation. The negative evidence approach might be the only logical way to confirm hauntings. A problem arises when you can’t rule out all rational explanations, but can’t rule out paranormal phenomenon. All this leaves us with is inconclusive evidence. It is were many hauntings lay.
The most popular outlet for paranormal in the media is ghost stories and haunting investigations. The haunting investigator uses many tools, such as EVP, EMF. These tools aim to provide evidence, other than human senses. Like with other haunting, it is difficult to determine whether it is reporting variations in the environment or whether it is a genuine paranormal phenomenon. Investigators will need to rule out environmental causes to establish a paranormal phenomenon.
Of the experiences/investigations that can rule out human and environment factors, you are left with two types of hauntings. (1) those that interact with people and (2) those that don’t interact with people.