Cynthia Archer, who was an important member of Walker's staff when he was Milwaukee County executive and then served as deputy administration secretary when he became governor, did not respond to e-mails or phone messages, the Milwaukee Journal Sentinel reported. The agents would say only that they were involved in "a law enforcement action."
Neighbors said about a dozen agents arrived at 7 a.m. and stayed until 10 a.m.
Archer took a leave of absence last month for "personal family matters." She is expected to return to state government in a political job with the Department of Children and Families.
She has denied being a target of an investigation into the county executive's office, the Journal-Sentinel said. A staff member under Walker allegedly published online political commentary while she ws working.
Walker, a Republican, was at the center of a political battle over legislation stripping public employee unions of most collective bargaining rights.