Wis. Stat. § 856.03: Wills in court for safekeeping.

If a will has been filed with a court for safekeeping during the testator’s lifetime, the court on learning of the death of the testator shall open the will and give notice of the court’s possession to the person named in the will to act as personal representative, otherwise to some person interested in the provisions of the will. If probate jurisdiction belongs to any other court, the will shall be delivered to that court.