My ex wife's parents are planning to visit her and I want to protect my 9 year old son from spending time with them - especially the grandfather. He has a history of physically assaulting his wife. Last year, my son witnessed one such incident. This man is also extremely emotionally unstable and I saw my son being terrified of him when they were visiting my ex last year. Is there ANYTHING at all I can do legally to prevent my son from having to see him ? I live in Wisconsin. Also the grandparents are not US nationals.