Mich. Comp. Laws § 600.506

Sec. 506. (1) except as provided in subsection (2), the fifth judicial circuit consists of the counties of Barry and Eaton and has 2 judges. (2) If the county of Barry approves the reformation of the fifth judicial circuit pursuant to law and the county of Eaton approves the creation of the fifty-sixth judicial circuit pursuant to law, the fifth judicial circuit consists of the county of Barry and has 1 judge effective January 1, 1991.