Editor’s note: This article contains spoilers for Ghost, a film that came out 30 years ago. The supernatural fantasy romance film Ghost, in which Patrick Swayze and Demi Moore put on the Righteous Brothers and sex-demolish some pottery, snuck up on audiences in 1990 like a horny poltergeist. Made on a slim budget by a director primarily known for screwball comedies in which Leslie Nielsen bumbles his way through a series of international incidents, the movie was a surprise hit, and even that phrase isn’t quite strong enough. Ghost made over a half-billion dollars to become …