Wis. Stat. § 946.17
Any person who gives or agrees or offers to give anything of value to any person, for the service of such person or of any other person in procuring the passage or defeat of any measure before the legislature or before either house or any committee thereof, upon the contingency or condition of the passage or defeat of the measure, or who receives, or agrees to receive anything of value for such service, upon any such contingency or condition, or who, having a pecuniary or other interest, or acting as the agent or attorney of any person in procuring or attempting to procure the passage or defeat of any measure before the legislature or before either house or any committee thereof, attempts in any manner to influence any member of the legislature for or against the measure, without first making known to the member the real and true interest he or she has in the measure, either personally or as such agent or attorney, is guilty of a class A misdemeanor.
Wis. Stat. § 946.17