Wis. Admin. Code ERC § 70.06
As soon as possible after receipt and service of the personnel data, the commission shall, in writing, either direct an election, dismiss the petition, or make other orders regarding the disposition of the petition. In cases where the commission is directing an election, the direction shall establish the date on or before which an employee shall have been employed to be eligible to vote. The date shall be a date specified by the commission in the pay period in which the first timely petition was filed under this chapter regarding the bargaining unit, or another date specified by the commission. The direction of election shall provide that all individuals on the list provided by the municipal employer and on the list, if any, provided by a petitioning labor organization shall be allowed to vote, subject to the right of the municipal employer and any petitioning labor organization to challenge the eligibility of the voter.
Wis. Admin. Code Employment Relations Commission § ERC 70.06