Mich. Comp. Laws § 397.212

Sec. 12. Except as otherwise provided in section 10b, sections 10a and 11 do not apply to a city, village, or township maintaining a public library under a special act or to a public library contained in the 1979 statement prepared by the state board for libraries pursuant to section 8 of Act No. 59 of the Public Acts of 1964, being section 397.38 of the Michigan Compiled Laws. However, an existing public library may, by petition, be organized under section 10a regardless of the library's original organization.