Wis. Stat. § 97.61

Foods, beverages and ingredients from commissaries outside the state may be sold within the state if such commissaries conform to the provisions of the food establishment sanitation rules of this state or to substantially equivalent provisions. To determine the extent of compliance with such provisions, the deFOOD, LODGING, RECREATION 97.61725 partment may accept reports from the responsible authority in the jurisdiction where the commissaries are located.