Mich. Comp. Laws § 600.8133

Sec. 8133. (1) Except as provided in subsection (2), the sixty-sixth district consists of the county of Shiawassee, is a district of the first class, and has 2 judges. (2) Beginning on the earlier of the following dates, the sixty-sixth district has 1 judge: (a) The date on which a vacancy occurs in the office of district judge in the sixty-sixth district. (b) The beginning date of the term for which an incumbent district judge in the sixty-sixth district no longer seeks election or reelection to that office.