Wis. Stat. § 786.15: Realty of wards, validity of the conveyance.

Every deed, mortgage, lease or other conveyance made in good faith by the guardian of a minor or individual adjudicated incompetent, pursuant to any order or judgment of a circuit court, made under the provisions of this chapter, shall be as valid and effectual as if made by the minor when of full age or by the individual adjudicated incompetent before the adjudication.