Wis. Stat. § 172.06
If no claimant for an animal taken up under s. 172.02 causes its return, and if the animal has not been appraised for more than $10, the finder shall become the absolute owner of the animal. If the appraised value of the animal exceeds $10, the animal shall be sold at public auction by the sheriff or any constable of the county on the request of the finder. Notice of the sale shall be given and the sale shall be conducted and the same fees allowed as in the case of sales upon execution under ch. 815. The finder may bid at the sale and shall at the time of sale deliver to the officer conducting the sale a statement in writing of the finder's charges, which shall be filed by the officer with the municipal treasurer. After deducting the finder's charges, if just and reasonable, and the costs of the sale, the officer shall pay one-half of the remaining proceeds to the finder and, within 10 days after the sale, the other half to the treasurer of the municipality for its use. If the finder of any stray neglects or refuses to cause a sale to be made when required by law, the finder shall pay to the municipality the value of the stray, to be recovered in an action by the municipality.
Wis. Stat. § 172.06