Danger Signal is a 1945 American film noir starring Faye Emerson and Zachary Scott.

A mysterious pulp writer—and psychopath—named Ronnie Mason, steals a dead woman's wedding ring and money and leaves a fake suicide note.

The woman's husband, Thomas Turner, when questioned by the local police, believes his dead wife might have been seeing Mason behind his back.

Mason leaves town, changes his name to Marsh and, displaying a noticeable limp he acquired jumping from the dead woman's bedroom window and a veteran's pin he steals from a fellow passenger on the L.A. bus, passes himself off as a wounded veteran and rents a room in a house Mrs. Fenchurch shares with her elder daughter Hilda, a public stenographer, and the teenaged Anne.

All three women are extremely impressionable, and to the consternation of professor Andrew Lang, who secretly loves Hilda, the girls fall for Marsh's charms.