Wis. Stat. § 818.24: Exoneration of bail.

The bail may be exonerated either by the death of the defendant or imprisonment in the Wisconsin state prisons, or by discharge from the obligation to be amenable to the process, or by surrender to the sheriff of the county where arrested, in execution thereof, within 20 days after the commencement of the action against the bail or within such further time as may be granted by the court.