Mich. Comp. Laws § 750.137: Purchases from minors.

Sec. 137.

A dealer in second-hand goods, junk shop keeper, peddler, rag or paper buyer, pawnbroker or hawker who purchases either directly or indirectly or by his agent or clerk, any goods, thing, article or articles from a minor without the written consent of the parent or guardian of the minor shall be guilty of a misdemeanor.