Shot in ten days on a budget just under $60,000.
Writer/director Leslie Stevens used his house in the Hollywood Hills as Ann Carlyle's home in the movie - and the real empty house next door.
Director/writer Leslie Stevens and Kate Manx (Ann) were married in 1958, a year before this film was shot. They were divorced in 1964, and she died from a reported overdose a few months later that same year.
Thought to have been lost for more than 30 years, it has been preserved and restored by the UCLA Film and Television Archive.