Wis. Stat. § 60.43: Financial audits.

(1) General. The town board may provide for financial audits under s. 66.0605.

(2) Audit of combined clerk and treasurer office. If the offices of town clerk and town treasurer are combined under s. 60.305 (1) (a), the town board shall arrange for an audit of the town financial records at least once every year. The audit may be conducted either by a certified public accountant, appointed by the town board and not otherwise employed by the town, or by the department of revenue if the department provides such a service.