Mich. Comp. Laws § 409.112a

Sec. 12a. A minor who would otherwise be permitted under this act to be employed in an occupation subject to this act shall not be employed in an occupation that involves a cash transaction subject to this act after sunset or 8 p.m., whichever is the earlier, at a fixed location unless an employer or other employee 18 years of age or older is present at the fixed location during those hours.