For the purpose of attacking the credibility of a witness, evidence of bias, prejudice, or interest of the witness for or against any party to the case is admissible.
Wis. Stat. § 906.16
Sup. Ct. Order No. 16-02A states that: "The Judicial Council Notes to Wis. Stats. 901.07, 906.08, 906.09, and 906.16 are not adopted, but will be published and may be consulted for guidance in interpreting and applying the rule."