Mich. Comp. Laws § 460.804

Sec. 4. (1) "Municipal bond" means a bond or note or other evidence of indebtedness payable from ad valorem taxes which a governmental unit may issue. (2) "Municipal electric utility system" means a system owned by a municipality or combination of municipalities to furnish heat, power, and light. (3) "Municipality" means a city, county, incorporated village, township, or metropolitan district of this state, or a board, agency, or commission thereof, owning a system or facility for the generation, transmission, or distribution of electric power and energy for public or private use, or proposing to own such a system or facility.