The Toy Box (1971)

Ralph convinces his girlfriend, Donna, to join a strange gathering at his family's mansion, where attendees are required to enact risqué performances before a corpse—his wealthy uncle. Each participant is lured by the promise of treasures from the mysterious "toy box." As Ralph and Donna wait for their moment on stage, the eerie atmosphere intensifies when the mansion’s doors seal shut at midnight. Soon, they realize that the performers are mysteriously being killed off, and the source of the terror appears to be the very uncle they thought was lifeless.