Wis. Stat. § 452.23

(1) A broker or salesperson may not disclose to any person in connection with the sale, exchange, purchase or rental of real property information, the disclosure of which constitutes unlawful discrimination in housing under s. 106.50 or unlawful discrimination based on handicap under 42 USC 3604 , 3605 , 3606 or 3617 .

(2) A broker or salesperson is not required to disclose any of the following to any person in connection with the sale, exchange, purchase or rental of real property: (a) That the property was the site of a specific act or occurrence, if the act or occurrence had no effect on the physical condition of the property or any structures located on the property. (b) Except as provided in sub. (3) , information relating to the physical condition of the property or any other information relating to the real estate transaction, if a written report that discloses the information has been prepared by a qualified 3rd party and provided to the person. In this paragraph, “qualified 3rd party" means a federal, state or local governmental agency, or any person whom the broker, salesperson or a party to the real estate transaction reasonably believes has the expertise necessary to meet the industry standards of practice for the type of inspection or investigation that has been conducted by the 3rd party in order to prepare the written report. (c) The location of any adult family home, as defined in s. 50.01 (1) , community-based residential facility, as defined in s. 50.01 (1g) , or nursing home, as defined in s. 50.01 (3) , in relation to the location of the property. (d) Except as provided in s. 452.24 , any information related to the fact that a particular person is required to register as a sex offender under s. 301.45 or any information about the sex offender registry under s. 301.45 .

(3) A broker or salesperson shall disclose to the parties to a real estate transaction any facts known by the broker or salesperson that contradict any information included in a written report described under sub. (2) (b) .

(4) In performing an investigation or inspection and in making a disclosure in connection with a real estate transaction, a broker or salesperson shall exercise the degree of care expected to be exercised by a reasonably prudent person who has the knowledge, skills and training required for licensure as a broker or salesperson under this chapter.