Michigan Compiled Laws, Chapters 81 to 113 Fourth Class Cities § 85.17

Sec. 17. In case any vacancy occurs in the office of mayor, or in any other elective office, except justice of the peace, constable and school trustee, as hereinafter provided, the council may fill such vacancy by appointment at any time within 20 days after such vacancy occurs, or may, within such time, call a special election for the purpose of filling such vacancy, as they may deem for the best interest of the city. Vacancies in the office of justice of the peace and constable shall be filled at the next annual election or at a special election called for that purpose. Vacancies in any appointive office shall be filled within 20 days after such vacancy occurs, by the mayor by and with the consent of the council.