Mich. Comp. Laws § 168.512
Any elector of the municipality may challenge the registration of any registered elector by submitting to the clerk of that municipality a written affidavit that such elector is not qualified to vote, which affidavit shall specify the grounds upon which the challenged elector is disqualified. Upon receipt of such affidavit, the clerk shall forthwith send by registered or certified mail to the challenged elector at his registered or last known address a notification of the challenge, which shall include the grounds for such challenge as stated in the affidavit. The challenged elector may within 30 days appear before the clerk and answer the questions and take the oath required of persons challenged on the same grounds at election, or in lieu of appearing in person the challenged elector, within a like period of time, may elect to file with the clerk an affidavit setting forth specifically his qualifications as an elector of the municipality and answering the grounds of the challenge. If within the 30-day period the person challenged shall fail to appear and be sworn or to file an affidavit, or if his statements do not show him to be a qualified elector of the municipality, the clerk shall forthwith cancel his registration. The 30-day period referred to in this section shall be the 30 days immediately following the date of mailing the notice to the challenged elector.
Any person who shall challenge under the provisions of this section, indiscriminately and without good cause or for the purpose of harassment, shall be guilty of a misdemeanor.
MCL 168.512