Wis. Stat. § 13.23
Any person wishing to contest the election of any senator or member of the assembly shall, within 30 days after the decision of the board of canvassers, serve a notice in writing on the person whose election the contestant intends to contest, stating briefly that the election will be contested and the cause of such contest, and shall file a copy thereof in the office of the elections commission at least 10 days before the day fixed by law for the meeting of the legislature. The elections commission shall then send a copy of s. 13.24 to both contestants. If any contestant fails to so file a copy of such notice, the contestant shall not be entitled to any mileage or salary in case payment has been made therefor to the sitting member.
Wis. Stat. § 13.23