Was that based a book.
I have a book on my kindle that I think has that title. It’s very good.
The one I saw was made in 1944 and was also based on the Lowndes book.
Five films in all have been made based on the book.
In truth, let's say most of the films, if not all, were based "loosely" on the novel as it was written....but they were all successful....and some are enjoyed immensely to this day.
It's worthwhile to look up Marie Belloc Lowndes on Wiki. She came from a famous British family (the Bellocs) that produced some incredibly notable, talented and outstanding figures in the Victorian era and after.
Marie Lowndes, a prolific writer, had a reputation for writing books that we would call "psychological thrillers" today. "The Lodger" was one of them.
Leni