Wis. Stat. § 859.33: Contest of claims; procedure.

(1) How contest initiated. The following persons may contest a claim or assert an offset or counterclaim in court: the personal representative, a guardian ad litem or a person interested who has the approval of the court. They may do so only by mailing a copy of the objection, offset or counterclaim to the claimant or personally serving the same upon the claimant and filing the same with the court. The objection, offset or counterclaim may be served at any time prior to entry of judgment on the claim, but if a copy of the claim has been mailed to or served upon the personal representative or the attorney for the estate, the objection, offset or counterclaim shall be served upon or mailed to the claimant and filed with the court within 60 days after the copy of the claim was mailed to or served upon the personal representative or the attorney for the estate. The personal representative shall not be obligated to assert any offset or counterclaim in court and may, if he or she deems it to be in the best interests of the estate, assert the offset or counterclaim in any separate action otherwise authorized by law outside the court proceedings. Any offset or counterclaim so asserted shall be deemed denied by the original claimant.

(2) Procedure. If any claim, offset or counterclaim is contested, the court may require the issues to be made definite, fix a date for pretrial conference and direct the manner in which pleadings, if any, shall be exchanged. The court shall set a time for trial upon its own motion or upon motion of any party.