Shirley Jackson was not impressed with this filmed adaptation of her novel "The Bird's Nest". Her assessment: "Abbott and Costello meet a multiple personality." (From Ruth Franklin's 2016 biography "Shirley Jackson: A Rather Haunted Life".)
This movie was MGM's rival to the hit The Three Faces of Eve (1957), released 4 months earlier, which won an Oscar for Joanne Woodward. Both movies are about a young woman's multiple personalities and the doctor who helps her with hypnotism.
Kirk Douglas' production company was involved in developing this movie. Douglas claimed that he was unenthusiastic about the project from the outset and disappointed with the result.
Aunt Morgan's front-loading washing machine is a Bendix model "S", circa 1947 - one of the first home front-loaders sold after WWII.