The High Chaparral (1967)

S3E21 The Reluctant Deputy

Blue falls prey to a practical joke that leads him to become a temporary deputy marshal. After being duped into taking the oath by Manolito and Uncle Buck, he unexpectedly finds himself in charge when the town's usual lawman leaves. Now with newfound authority, Blue seizes the opportunity to get back at both Manolito and Buck in a satisfying twist of fate.