The Wrong Husband by Ruth Ann Nordin
After winning back the money his uncle gambled, Owen gives it to his aunt. But Big Roy isn't happy, and he sends men to kill Owen. Owen flees to Nebraska where he finds a Wanted poster seeking his arrest.
Scared, he plays along with the sheriff who thinks he's Irving, the new deputy. Irving was to marry Jenny Larson and since she's pretty, Owen plays along. But then Irving shows up, and that's when things get really interesting.