Ghostbusters the movie(s) (and animated TV show?) was a comedy and being silly with its classifications.

There’s at least one role-playing game system based on Ghostbusters, which no doubt somewhere have a list of ghost types.

I would probably not refer to much of anything from Ghostbusters in comparison to other contexts that categorize ghosts.

There are a lot of different people & groups & cultures who have categorized them in different ways. I hardly know where to begin.

In the Dewey Decimal System (your library), Ghosts are classified in the 130s -

130 Paranormal phenomena
130.1 Philosophy and theory
131 Occult methods for achieving well-being
133 Parapsychology & occultism
133.1 Apparitions
133.3 Divinatory arts
133.4 Demonology and witchcraft
133.5 Astrology
133.6 Palmistry
133.8 Psychic phenomena
133.9 Spiritualism
135 Dreams & mysteries
137 Divinatory graphology
138 Physiognomy
139 Phrenology

@elbanditoroso That is very helpful. Mods don’t delete. I will go to the library this week now and loiter about the 130’s.

You have asked this on Friday the 13th..) I don’t know why people are afraid of this number so much!!

@elbanditoroso Back from the library got three books on parapsychology .They had 50 books to choose from on the subject.

1. Deliberate hoax
2. Person experiencing a hallucination due to mental illness or other internal mental phenomena
3. Person misinterpreting actual physical phenomena as paranormal

How can you tell if something (someone?) is a ghost? Is there a scientific test for it? Are all ghosts the earthbound souls of the departed, or is there some other mechanism that produces them? Are leprechauns a type of ghost? Check to see if your parapsychology books have the answers. I suspect not. It appears that there is room for some Nobel laureate level investigation into this area.

2 primary classifications:
1. Existent.
2. Non-existent.

@kritiper, I was just going to say the same thing. With group 1, of course, being empty.