(1) If under formal administration final judgment is not entered in an estate within 18 months after filing of the petition for administration and the estate is not open pursuant to an order extending time, the judge shall order the attorney and the personal representative for the estate to show cause why final judgment has not been entered and shall proceed under s. 857.09.
(2) If under informal administration under ch. 865 the estate has not been closed by sworn affidavit within 18 months after filing of the petition for administration and the estate is not open pursuant to an order extending time, the probate registrar shall order the personal representative for the estate to show cause why the estate has not been closed. If cause is not shown the probate registrar shall appoint a new personal representative acceptable to all interested parties other than creditors of the deceased who shall proceed under ch. 865.