Carry On Cowboy (1965)

Stodge City is in the grip of the Rumpo Kid and his gang. Mistaken identity again takes a hand as a 'sanitary engineer' named Marshal P. Knutt is mistaken for a law marshal. Being the conscientious sort, Marshal tries to help the town get rid of Rumpo, and a showdown is inevitable. Marshal has two aids—revenge-seeking Annie Oakley and his sanitary expertise.