Dos fantasmas y una muchacha (1959)

At the beginning of the 20th century, two men fight a duel in a theater over a beautiful young performer. They are both killed in the duel, and after their death their ghosts haunt the theater. Many years later the ghosts run into a beautiful young girl who they believe is a descendant of the woman they fought the duel over, and they discover that she is in danger from a gang of bank robbers.