Mihalko said federal prosecutors plan to file charges, but U.S. Attorney's Office spokeswoman Robin Zier said Tuesday she could neither confirm nor deny that.
Authorities searched the home last week after a meter reader discovered some mail on the back deck of the home. Mihalko said the employee recently resigned. The person's name has not been released.
Most of the mail appeared to be fliers and coupons, though agents are searching for first-class mail that may need to be delivered immediately.