Wis. Stat. § 973.02: Place of imprisonment when none expressed.

Except as provided in s. 973.032, if a statute authorizes imprisonment for its violation but does not prescribe the place of imprisonment, a sentence of less than one year shall be to the county jail, a sentence of more than one year shall be to the Wisconsin state prisons and the minimum under the indeterminate sentence law shall be one year, and a sentence of one year may be to either the Wisconsin state prisons or the county jail. In any proper case, sentence and commitment may be to the department or any house of correction or other institution as provided by law or to detention under s. 973.03 (4).