Off Beat (1986 film)

Off Beat is a 1986 comedy film about a young librarian who impersonates a police officer. The film was directed by Michael Dinner, and stars Judge Reinhold, Meg Tilly, and Cleavant Derricks.

A mistake he makes inadvertently messes up Washingtons undercover work. Joe now owes him a favor, but is unprepared for what Washington wants. A police charity event needs officers to dress in drag, but because Washington wants no part of that, he asks Joe to take his place.A reluctant Joe decides to go through with the audition, expecting to be so bad that he wont be cast in the show. When he goes there and meets an attractive policewoman, Rachel Wareham, it changes everything. Joe not only does the show, he continues to keep from Rachel the fact that hes not a real cop. ........

Source: Wikipedia