Tales of the Unexpected - The Colonel's Wife by W. Somerset Maugham (under 1/2 hour)
This entire series is on youtube if you like these kind of stories. I'm attaching one video below that I liked. There are many more episodes.
https://en.m.wikipedia.org/wiki/Tales_of_the_Unexpected_(TV_series)
Tales of the Unexpected (Roald Dahl's Tales of the Unexpected) is a British television series that aired between 1979 and 1988. Each episode told a story, often with sinister and wryly comedic undertones, with an unexpected twist ending.
The series originally adapted various stories from Roald Dahl's anthology books. Despite being produced on a low budget, the series attracted notable guest stars, including Susan George, Siân Phillips, José Ferrer, Joseph Cotten, Janet Leigh, John Gielgud, John Mills, Wendy Hiller, Denholm Elliott, Katy Jurado, Joan Collins, Rod Taylor, Ian Holm, Brian Blessed, Siobhán McKenna, Brad Dourif, Michael Gambon, Cyril Cusack, Julie Harris, Michael Hordern, Derek Jacobi, Anna Neagle, Elaine Stritch, Andrew Ray, Harry H. Corbett, Zoë Wanamaker, Charles Dance, Michael Ontkean and Timothy West./div]