Wis. Stat. § 757.23

A municipal, circuit, or supplemental court commissioner, or any judge acting as a court commissioner, shall not act or take part in the decision of, or make any order in any matter or proceeding in which he or she is a party, or in which his or her rights would be in any manner affected by his or her decision or order thereon, or in which he or she is interested, or in which his or her law partner, or any person connected with him or her as employer, employee or clerk, or in the law business in any manner, shall be interested or appear as a party, agent, attorney or counsel. Any municipal, circuit, or supplemental court commissioner or judge, acting as a court commissioner, violating this section shall forfeit $25 for each violation, and shall also be subject to removal from office.