I think this might be one of the c. 1930's-40's Minnesota pinball tokens, listed in Alpert & Smith's book, Video Arcade, Pinball, Slot Machine, and Other Amusement Tokens of North America, as "NSN (incuse on a raised star) [reverse] (same as obverse)." Size 20mm. Struck in brass, nickel-plated brass, and white metal.