Mich. Comp. Laws § 168.67
If a vacancy occurs in the office of governor, the powers and duties of that office shall devolve upon the lieutenant governor for the remainder of the term or until the disability ceases. If the lieutenant governor succeeds to the office of governor, or if a vacancy occurs in the office of lieutenant governor, the senate, by resolution, with a record roll call vote, shall appoint an acting lieutenant governor of the same political party as the governor who shall serve for the remainder of the term or until the disability ceases. If a vacancy occurs in both the offices of governor and lieutenant governor, the elected secretary of state, the elected attorney general, the senate president pro tempore, and the speaker of the house of representatives, in that order shall act as governor until the vacancy is filled or the disability of either the governor or lieutenant governor ceases, as provided in section 26 of article 5 of the state constitution of 1963. Should the governor-elect die or fail to qualify by the first of January next following his or her election, the lieutenant governor-elect shall qualify and exercise all the powers and duties of the office of governor for the entire term, or until the governor-elect shall qualify. Should the lieutenant governor-elect also die or fail to qualify, the powers and duties of the office of governor shall devolve upon the secretary of state-elect and the attorney general-elect in that order in a like manner.
MCL 168.67