Roald Dahl’s Tales of the Unexpected: The Landlady.

The unnamed Landlady (Siobhan McKenna) is the titular main villainess from "The Landlady", episode 1.05 of Tales of The Unexpected (airdate April 21, 1979), based on the Roald Dahl short story of the same name. The episode begins with Billy Weaver (The main protagonist), arriving in Bath as part of a work trip. While there, he looks for accomdation, and sees a bed and breakfast sign in the window of a house. The unnamed woman then invites him in, claiming that a hotel he had been planning to stay at was booked out. Although finding the landlady's overly friendly demeanour off-putting, Billy decides to spend the night.