You know, I've actually thought of something similar. After becoming involved with ghost hunting, I learned about out of body experiences. I
wondered if people experiencing an OBE could actually be responsible for ghosts; people in their physical bodies just associated the OBE'er with
ghosts. Reality check, all of these things are PARANORMAL, so it's very difficult to attach one of them as an explanation for another. Personally,
I believe ghosts are spirits of the deceased.