The Dare-Devil.

The movie makers are filming the next installment of the western serial "Get Your Man". The movie's leading man wants his stunt double to do the next dangerous stunt. Purely by accident, a hapless, cross-eyed aspiring actor named Joe Magee ends up doing the stunt perfectly. He ends up doing dangerous stunt after stunt, all by accident, that fit the movie so perfectly that the movie's leading lady wants him in the picture. The exasperated director finds that getting Joe to do the stunts on command is an entirely different story.