He does not attribute one single experience to what we might term a "ghost" for lack of a better term. Witches, poltergeists, goblins, gremlins, fairies, dwarfs—all of them are real, physical, alive, being either the real thing or the teleported or telepathed image of the real thing.
1947 June, Raymond A. Palmer, “Observatory”, in Amazing Stories, volume 21, number 6, page 9