Premise: The Ghost and Mrs. Muir (1947) is a romantic-fantasy film starring Gene Tierney and Rex Harrison. It was directed by Joseph L. Mankiewicz, and is based on a 1945 novel written by Josephine Leslie under the pseudonym of R. A. Dick. In 1945, 20th Century Fox bought the film rights to the novel, which had been published only in the United Kingdom at that time. It was shot entirely in California.
Hypothesis:  Josephine Leslie wrote the novel that inspired the movie The Ghost and Mrs. Muir