At the hearing upon such order or warrant such judgment debtor may be examined on oath and testimony on the part of either party may be offered.
Wis. Stat. § 816.06
A judgment creditor may examine the spouse of a judgment debtor in regard to the amount and location of marital property that might be available to satisfy a judgment. Courtyard Condominium Association, Inc. v. Draper, 2001 WI App 115, 244 Wis. 2d 153, 629 N.W.2d 38, 00-1817. This section does not grant a judgment creditor the right to compel a non-judgment debtor third party to testify at supplemental proceedings. Crown Castle USA, Inc. v. Orion Logistics, LLC, 2012 WI 29, 339 Wis. 2d 252, 811 N.W.2d 332, 09-3029.