premise: The entire cast of Ghost is comprised of actual ghosts.
hypothesis: In folklore , a ghost ( sometimes known as an apparition , haunt , phantom , poltergeist , shade , specter or spectre , spirit , spook , and wraith ) is the soul or spirit of a dead person or animal that can appear to the living . Ghost is a 1990 American romantic fantasy thriller film starring Patrick Swayze , Demi Moore , Whoopi Goldberg , Tony Goldwyn , and Rick Aviles .