Wis. Stat. § 53.29: Proceedings in more than one state.

Except for a petition for the appointment of a temporary guardian or issuance of an order limited to property located in this state under s. 53.24 (1) (a) or (b), if a petition for the appointment of a guardian of the person or issuance of an order appointing a guardian of the estate is filed in this state and in another state and neither petition has been dismissed or withdrawn, all of the following rules apply:

(1) If the court in this state has jurisdiction under s. 53.23, it may proceed with the case unless a court in another state acquires jurisdiction under provisions similar to s. 53.23 before the appointment or issuance of the order.

(2) If the court in this state does not have jurisdiction under s. 53.23, whether at the time the petition is filed or at any time before the appointment or issuance of the order, the court shall stay the proceeding and communicate with the court in the other state. If the court in the other state has jurisdiction, the court in this state shall dismiss the petition unless the court in the other state determines that the court in this state is a more appropriate forum.