In Borrowed Plumes (1926)

Mildred Grantley, a penniless society girl who wants to be an actress, passes herself off as the Countess D'Autreval. Through a mutual friend, Mildred gets to know the wealthy Dean family, falling in love with Philip Dean, a handsome young bachelor. A woman claiming to be the real countess shows up and persuades Mildred to introduce her to the Deans. Mrs. Dean smells a rat, however, and hires a detective who exposes the woman as a famous international crook. The honest-to-goodness countess finally shows up, and Mildred and Philip enter that haven of happiness open only to true lovers.