Wis. Stat. § 860.13: Who not to be purchaser, mortgagee or lessee without court approval.

The personal representative may not be interested as a purchaser, mortgagee, or lessee of any property in the estate unless the purchase, mortgage, or lease is made with the written consent of the persons interested and of the guardian ad litem for minors and individuals adjudicated incompetent or with the approval of the court after petition and hearing on notice given under s. 879.03 to all persons interested, or unless the will of the decedent specifically authorizes the personal representative to be interested as a purchaser, mortgagee, or lessee.