Temporary guardianship of an adult?

Okay so My fianc�e got into a car accident and his mom perused power of attorney and temporary guardianship we live in wisconsin and his dad was in idaho his mom called his dad and sent him a paper that she typed up to give her power of attorney his dad came here and is having problems with the way his mother is doing things the paper that he signed being that it was not notarized or even a legal document can he have dismissed to gain power of his son back? If so how would he go about it or did he even loose his control over his son being it wasnt a legal document and there was no lawyer there when he signed it. He thought he was just giving power of attorney as thats what he was told that she needed to make medical decisions but she really was going for guardianship. The only person that was there was a friend of hers that faxed the paper back to her what should his next step be now?