Wis. Stat. § 343.027: Confidentiality of signatures.

Any signature collected under this chapter may be maintained by the department and shall be kept confidential, except that the department shall release a signature or a facsimile of a signature to the department of revenue for the purposes of administering state taxes and collecting debt, to the elections commission, in electronic or digital format, for the purposes specified in s. 6.30 (5), to the person to whom the signature relates, to a court, district attorney, county corporation counsel, city, village, or town attorney, to a law enforcement agency, or to the driver licensing agency of another jurisdiction.