Governor and Lieutenant Governor†: A qualified elector* of the state at the time of taking office. Article V, Section 2, Wis. Constitution.
*Qualified elector is defined in s.6.02, Stats., as a U.S. citizen, 18 years of age or older, who has resided in the election district for at least 10 days before any election at which he or she offers to vote (and who is not disqualified by virtue of one or more of the impediments described in s.6.03, Stats.).
†No person may hold any state or local elected office in Wisconsin if the person has been convicted of a felony in any court in the United States unless the person has been pardoned of the conviction. No person may have his/her name placed on the ballot for any state or local elected office in Wisconsin if the person has been convicted of a felony in any court in the United States unless the person has been pardoned of the conviction. Article XIII, Section 3 (2), (3), Wis. Constitution.
Nobody 18 years old should be running for a major statewide office. Minimum age requirement for statewide ought to be 30, same with U.S. Senators. State legislature ought to be 25.