Since I've already looked at cryptozoology and pseudoscience, and since I've made a thermodynamic calculation about how much useful energy should be made available to a ghost using the assumptions made by The Ghost Hunters, I might as well go ahead and apply the standards of pseudoscience to the latter.
Once again let me emphasize that the problem with pseudoscience is a problem of the method and mental attitude. If something claims to be scientific, there are certain standards it should meet. Pseudoscience is not even science done badly; it is something entirely different that wants to be mistaken for science.
So before we even get started, there are those who will start out in a huff because they have seen a ghost, or at least they believe they have. Maybe they have. I do not categorically reject the existence of ghosts, although caution should be exercised in any particular case. It's like the situation in the Cold War when someone said their neighbor was a Soviet spy; it could be, since such spies really did exist, but in most cases it was probably just an over-active imagination.
So let's go back to the list of "defining characteristics" from
What Science Is And How It Works, by Gregory N. Derry.
1. Static or Randomly Changing Ideas.
This appraisal is complicated by the question of whose ideas are being discussed.
The Ghost Hunters and TAPS themselves have rather static ideas of uncertain origins, and such changes as we see on television may well be the result of television decisions. For instance, in the first season or so they sometimes had a Protestant friend attempt to cast out evil spirits in the Name of Jesus. The disappearance of this feature has been the most noteworthy change to their procedure. Otherwise, if you've seen 3 or 4 episodes, you've pretty much seen everything.
If we talk about the wider group of people who are either now "ghost hunting" or who have done so in the past, we see wildly changing ideas. The ideas espoused by groups like TAPS are quite different from those held by "psychic investigators", which in turn are rather different from those of the Spiritualists of the 19th and early 20th centuries. All of these ideas are very different from the traditional ideas of Christianity, Judaism, and Islam, and also from the ideas of classical paganism. As far as I can tell, the variations of ideas come from a few "inspired" individuals (the Fox sisters, for example) with radically new ideas, which are then adopted and adhered to in a rather static way.
2. Vague Mechanisms to Acquire Understanding.
Example: Ghost hunting groups claim that hauntings are more likely to occur near limestone, quartz, or water. Of course, any reported haunting must be reported by some living person, and people have always tended to live near water. Also, both limestone and quartz are extremely widespread. My home state, Florida, not only is a peninsula surrounded by water and with large numbers of rivers and ponds, it also consists largely of quartz sand and limestone rock. Finally, it might well be the case that there are correlations in the upbringing, life experiences, and tastes of those who choose to live in one area vs. those who choose to live in another. For example, it may be that those who choose to live in dry, barren regions may see themselves as no-nonsense realists who have no time for ghosts. They may be less likely to imagine ghosts, or alternatively, to dismiss any real ghosts they may see.
It does not seem that any serious effort has been made to control for these considerations. Instead, it appears that some ghost hunters have noticed water, limestone, or quartz near what they believe to be a residual haunting and made a leap in judgment.
3. Loosely Connected Thoughts.
Writings from the nineteenth century regularly use "magnetism" as a synonym for what is today called the paranormal. The only real connection seems to be that both are invisible forces of which most of the public had no real understanding. It is less humiliating to assume that two things you don't understand are really just two examples of one thing you don't understand.
(To be fair, the more well-educated might also point out Galvani's experiment in which electricity made a dead frog kick -- the basis for the story of Dr. Frankenstein -- and the growing evidence that electricity and magnetism were related. I don't think that really had much impact on how widely used the term was, though.)
The same thing happens today. In fact, it seems to be the basis of the assumption that ghostly activity should be detectable as an electric or magnetic field. Electromagnetism is still almost a complete mystery to the general public, even though it is understood quite well by those with the right education.
Likewise, ghost hunters will frequently insist that spirits are a form of energy, and that the survival of a spirit after death is an example of the conservation of energy. This is the result of a bad misunderstanding of what energy is and a failure to notice that the heat energy of a warm, dead body is in fact conserved -- it is just lost to the environment as the heat is lost and the body grows cold. Conservation of Energy (the First Law of Thermodynamics) is not the problem; loss of organization (the Second Law of Thermodynamics) is the problem.
Let's not even get started on how the word "dimension" is misused....
4. Lack of Organized Skepticism.
TAPS may say they look for explanations to "debunk" claims, but that is not really what is meant by organized skepticism. Something more on the order of peer review is intended, and there is nothing like that in paranormal investigations. In fact, there is usually not enough skepticism of any kind. The ghost hunters seem very quick to identify words and phrases from "electronic voice phenomena" (EVPs), even though most "voices" use monosyllabic "words" that require a great deal of imagination to decipher. To be perfectly honest, I think many of these "voices" are rumblings from their tummies as they carry the recorders around just above their belly buttons.
5. Disregard for Established Results.
When they attempt to use arguments from thermodynamics or electromagnetism without bothering to learn the basics of those sciences, I'd call that a disregard for established results.
Note that disregard does not necessarily mean that they deny the established results; they just don't have a real interest in what those results actually are.
The TV show is, after all, just a TV show, and it airs on what used to be called SciFi -- the Science Fiction Network. Not the Science Network. No one should be surprised that what they do is not good science, but in fact is pseudoscience.
Before closing, I would like to point out that Christianity has always forbidden necromancy -- the attempt to summon the dead so that they can perform some function or communicate. (Prayers to the saints, which someone is sure to bring up, are not the same thing, since all that is requested of the saints is that they will pray to God for us -- not a service and not communication.) If a ghost appears unbidden, I suppose it is permissible to speak to it, though great care should be taken in believing a spirit solely on the basis of its appearance. The best advice I have heard is to pray for the spirit; if it is indeed a soul in Purgatory, it could use the help, and if it is a soul or demon from Hell, at least it has not deceived you into doing anything wrong. One way or the other, there seems to be no moral difference in attempting to summon a spirit using a mirror or basin, a Ouija board, or an electromagnetic field detector. It's a bad idea; don't do it.
Interestingly enough, Fr. Herbert Thurston was convinced years ago that some, at least, of the Spiritualistic manifestations were genuine -- at least of some preternatural origin -- but he knew quite well that most, if not all, of even the most reputable mediums were detected in fraud. He concluded that necromancy always has a degenerative effect on morals, and that even the "best" mediums would eventually fake a manifestation rather than disappoint an audience. I wonder if the Ghost Hunters have followed a similar trajectory, perhaps starting off sincerely (even though what they were doing was not really science) and only resorting to trickery towards the end. Certainly, there have been allegations of trickery.