"This is a paraphilia in which a person experiences sexual attraction to and sexual arousal by ghosts, spirits, and spectre figures in mirrors," CalExotics's resident sexologist, Dr. Jill McDevitt, told POPSUGAR. People get really into the fetish. In fact, "some people claim to have sex with ghosts," she says.
Why? "Because humans have always been obsessed with understanding their place in the world and life after death. And per the nature of fetishes, if it exists (and in the case of ghosts, even if it doesn't exist), a human can develop a sexual interest in it," she says. It might be hard to access "real" ghosts, but you can play up this fantasy on Halloween by decorating your home with ghost decor, using fog machines and imagery to create ghost-like reflections in mirrors, or asking your partner if they'll dress up, she suggests.