Ghost hunter groups claim to be scientific, and most give that appearance because they use high-tech scientific equipment. They employ equipment for a purpose for which it was not made and has not been shown to be effective.

TheEquipment used  by paranormal investigators is based on theory.

These theories are called basic beliefs which draw an inference of self-justifying or self-evident.  Theories provided by ghost investigators sound very scientific, but using scientific language does make it science. A theory qualifies as a good guess, a belief, or practice that is claimed to be scientific or made to appear scientific, but does not adopt the scientific method.  Preconceived beliefs can lead to self deception and false conclusions.

There is a big difference between good sound theories and theories that simply just sound good.  Propositions accepted as true without proof or demonstration would be more reasonable interpreted as wishful thinking instead of ,IOU an explanation.

"How sure do we need to be that our beliefs correspond to the actual world?

A ghost hunter is in a haunted location experiences a change in temperature His EMF meter is spiking high readings. His theory leads him to believe this may be evidence of a spirit trying to communicate. His theory justifies his belief a spirit is in the room.   

Do ghosts really emit electromagnetic fields? Are EMF meters even capable of demonstrating that ghosts emit EM fields?  

 To justify a belief with out evidence is no more then a theory of the belief. Our ghost hunter believes he is in the presence of a spirit, based on beliefs, of other beliefs. So the ghost hunter’s belief isn’t based on evidence. 

  In theory thek2 meter can communicate with spirits. The theory is ghosts emit an electromagnetic field as they move about. The meter can detect the field if the ghost is interactive, its movements can act as a response to a question being asked. The theory is based on the led lights move in response to questions and this can only be accomplished by communicating with a spirit. 

 So the justifying belief is the K2 can communicate with a spirit. And the justified belief is spirits are real. Because the K2 blinks in response to yes and no questions.  

But what if the belief is itself unjustified. It would in no way be one's intellectual right to suppose that only a spirit is responsible for the K2 responding to yes and no questions.

Does the K2 really provide an inference of reality based on a theory of belief to suggest a spirit can hear and understand us and manipulate an EMF meter? The theory amounts to nonsense because it is not saying the K2 could be used to communicate with spirits; it is saying ghosts do communicate with a K2 meter. It suggests we rule out the fact it lights up for nearby electrical lines and all other possibilities.

Stephen and Paul Anthony: you ask an excellent question that has been bugging me a long time.

Where does this theory of EMF:s being ghosts come from and what is it's basis?

I can't find any reference to the source of this theory and how it works anywhere. I just seems to be there and embraced by the paranormal field at large. It just seems to be an assumption pulled out of a magic hat or something, however portrayed as fact and spread to new ghosthunters who then spread to yet newer ghosthunters and noone seems to know the origins or actual basis for the theory. I mean, even if we believe in ghosts, what says the create EMF:s which they can manipulate by will? And how to separate normal background radiation from ghosts? Which ought to be a priority för a ghosthunter one would assume… 

But the big question that remains unanswered is: where does the theory come from?

 There is no agreement what they are if they do exist. The evidence for ghosts is no better today than it was a year ago, a decade ago, or a century ago.

It’s not whether something is "real" or not, but at what point does it go beyond the level of  Human understanding. You can't prove that humans are capable of understanding everything, but as a human, you certainly can't prove that humans aren't capable of understanding certain logical concepts, either. And my understanding is, ghosts do not exist.

Stephen, bullerspoke

Try this, God Helmet refers to a controversial experimental apparatus that stimulates the brain with magnetic fields. Dr. Michael A. Persinger

  http://www.spinvestigations.org/Michael_Persinger.pdf

I know of Persingers experiments, however they in no way explain why EMF detectors are thought to be able to detect ghosts, or why there is a theory that says that ghosts eminate EMF:s which they can manipulate at will.

Persingers experiment is focused on EMF:s and their effect on the brain and primarily perception. His experiments show that exposure to certain, controlled EMF:s make one see ghosts, or as Persinger himself states as a possibility, makes one able to see ghosts.

Unfortunately his experiment really does not say anything about EMF sensitivity, only that there can be effects of certain exposure of in a lab, he has not done any field tests, or what ghosts are or not EMF-wise.

He has shown a vague correlation, nothing more. But his work is still quite interesting. 

Ah, we found our culprit…

It would seem reasonable to assume that Auerbach and Taylor popularised the use of EMF detectors.

However, the question then becomes why did they start to use them and what science if any do they refer to as basis for their use? 

I found this on Auerbachs website:

"Typically, when we conduct investigations, we do use detectors of electromagnetic fields to provide additional sensors to anything unusual in the environment. Such equipment does not detect ghosts per se, but are useful in looking for physical correlates to the perceptions / sensations / experiences of the witnesses (including psychics). Do human beings have the capacity to detect anomalous magnetic fluxes in the environment? Or are these magnetic (and other detectable energetic anomalies) somehow "footprints" left behind by apparitions and haunting "imprints"?

We're still working on that, just as many scientists are working on the major question of Consciousness itself. After all, if technology cannot be used to detect consciousness IN the body, where we assume it is, how can it be used definitively to detect consciousness after death?"

http://www.mindreader.com/info_tech_ghost.html

In short he says, EMF are not ghosts per se, but they correlate with  paranormal experiences. Of course, it's all speculation and no fact except a vague correlation based in the subjective experience of a person or persons. In short, it's a belief not science.

It is a good example of belief bias and the latter part of the quote is  good example of  argumentum ad ignorantiam.