Wis. Stat. § 601.18

Any power, duty or function vested in the commissioner by law may be exercised, discharged or performed by any employee of the office acting in the commissioner’s name and by the commissioner’s delegated authority. Any person whose own course of action in good faith depends upon proof of the validity of an asserted delegation is not obligated to act until the person is shown a written delegation with a handwritten signature of the commissioner or deputy commissioner.