Wis. Stat. § 846.165: Application for confirmation of sale and for deficiency judgment.

No sale on a judgment of mortgage foreclosure shall be confirmed unless 5 days’ notice has been given to all parties that have appeared in the action. Such notice shall be given either personally or by registered mail directed to the last-known post-office address, mailed at least 5 days prior to the date when the motion for confirmation is to be heard, if any post-office address is known; if not known, mailing may be dispensed with but an affidavit shall be filed with the court stating that the address is not known, and the notice shall state, in addition to other matter required by law, the amount of the judgment, the amount realized upon the sale, the amount for which personal judgment will be sought against the several parties naming them, and the time and place of hearing.