Wis. Stat. § 858.13: When appraisal necessary.

Except as provided in s. 858.15 all inventoried property shall be appraised by one or more disinterested persons appointed by the court. The appraiser or appraisers shall appraise each item in the inventory which is required to be appraised and certify to its value. If the property is situated in 2 or more counties, one or more appraisers may be appointed for each county.