in this case you'll need to file an amended return in your home state reporting the wages and if the w-2c shows no PA w/h you'll need to pay. you also you need to file a nonresident amended return with WI to get the withholding back. do not be surprised if PA bills you for penalty and interest for any unpaid amount. this would be a discussion with your employer, but it may argue that you should have noticed the w/h was for the wrong state.
