The employer may not deduct labor organization dues from a general employee's earnings.
Wis. Stat. § 111.845
In the case of Wisconsin Education Association Council, et. al., v. Scott Walker, et. al., 824 F. Supp. 2d 856 (2012), the United States District Court for the Western District of Wisconsin declared 2011 Wis. Act 10, section 298, which created s. 111.845, to be null and void.
The creation of this section by 2011 Wis. Act 10 did not violate equal protection or free speech protections. Wisconsin Education Ass'n Council v. Walker, 705 F.3d 640 (2013).