Mich. Comp. Laws § 453.371

Sec. 1. That all persons duly appointed or chosen as marshals, deputy marshals, or policemen, by the proper officers of any of the agricultural or horticultural societies of this state, and designated by appropriate badges, shall, as such marshals and policemen during the days of the fairs or exhibitions held by any of said societies be vested with the police powers of special constables in the township, village, or city in which such fairs or exhibitions are held.