Wisconsin Statutes Employment, Compensation and Mining (Ch. 101 to 109) § 103.23. Age minimum

(a) Each minor must give the nonprofit organization, public school, private school, or tribal school written approval from the minor's parent or guardian.

(b) Each minor under 9 years of age or each group containing one or more minors under 9 years of age must be physically accompanied by a parent or a person at least 16 years of age.