Shock

Shock, starring Vincent Price, Lynn Bari, Anabel Shaw, Frank Latimer

Shock is an excellent film noir, where a woman, on the verge of a nervous breakdown, is waiting for her husband to return from World War II. Waiting at a hotel, in the next-door suite, there's a murder! And the sight pushes her over the edge! She's sent to a sanitarium, that unknown to all is run by … the murderer!

https://family-friendly-movies.com/film-noir/shock/