Mich. Comp. Laws § 38.521

Sec. 1. (1) A city, village, or township that has adopted the provisions of Act No. 78 of the Public Acts of 1935, as amended, being sections 38.501 to 38.518 of the Michigan Compiled Laws, may operate a police cadet training program. An applicant for enrollment in the program shall meet all the requirements of that act for a position in the police department, except that the applicant shall be not less than 18 years of age and not more than 31 years of age. A person enrolled in the program shall not fulfill any functions, other than administrative, of a police officer until he or she receives a favorable recommendation from the appointing officer to the civil service commission or to the appointing authority if there is no civil service commission. A police cadet recommended for advancement to police officer shall receive preferential consideration for the position over other applicants. A police cadet shall serve as a cadet for not more than 4 years. (2) Notwithstanding subsection (1), any cadet who is serving as a police cadet on or after March 31, 1983 shall be entitled to serve as a cadet for not more than 8 years. This subsection shall not apply on or after July 1, 1987.