Wis. Stat. § 6.02: Qualifications, general.

(1) Every U.S. citizen age 18 or older who has resided in an election district or ward for 28 consecutive days before any election where the citizen offers to vote is an eligible elector.

(2) Any U.S. citizen age 18 or older who moves within this state later than 28 days before an election shall vote at his or her previous ward or election district if the person is otherwise qualified. If the elector can comply with the 28-day residence requirement at the new address and is otherwise qualified, he or she may vote in the new ward or election district.