The horrific sounds made by the "dark shadows" are really the sounds of babies' cries, played at extremely slow speed backwards.
The role of Oda Mae Brown was not written with Whoopi Goldberg in mind, but Patrick Swayze was convinced she would be right for the part after seeing her one-woman Broadway shows.
When they were filming the chase scene at night in New York City, it was really cold, and everyone else was bundled up except for Patrick Swayze's character Sam Wheat, and since he's a ghost they didn't want his breath showing so they had him chew ice.
Sondra Rubin: Writer Bruce Joel Rubin's mother, who played the nun who faints over the size of the check that Oda Mae endorses.
Charlotte Zucker: Director Jerry Zucker's mother (who has appeared in many of the Zucker brothers' movies) plays the bank officer.
Susan Breslau: She is Jerry Zucker's real-life sister, and has a cameo playing the character Susan, named after her.