The Old Dark House
The Old Dark House is a 1932 Universal comedy horror film that is considered to be a main influence on the structure of The Rocky Horror Picture Show. Directed by James Whale, the film stars Boris Karloff (in his first film role after his success in Frankenstein), Charles Laughton, Gloria Stuart, Raymond Massey, Melvyn Douglas, Lilian Bond, Eva Moore, and Ernest Thesiger.
Like The Rocky Horror Picture Show, the film involves a couple (Massey and Stuart) that get lost while driving at night in a heavy storm, and seek refuge in a remote castle where they meet the strange Femm family and their butler Morgan (Karloff), along with other visitors to the house, including a chorus girl. Overnight debauchery, a dinner scene, a bizarre brother and sister (Moore and Thesiger), and other story beats seem to be direct influences on the The Rocky Horror Picture Show's plot line.
The Old Dark House at IMDb