Population of about a 1000.
For something that small, I doubt they actually need a police force. They probably spend the bulk of their time handing out speeding tickets or what not.
One full-time officer, who could have been the prototype for Barnet Fife, a part-time Chief, and about 5 part-time officers. The FT's most significant duty was to drive behind school buses to make sure nobody drove badly while the school bus was operating. The rest of the force covered weekends and evenings.
Pretty much exactly what the town residents wanted. Very few tickets were written, so the PD was not considered a profit center for the municipal government.