Child custody in wisconsin?

my boyfriend is trying to get 50/50 custody of my one month old daughter, but i feel he is a very unfit parent and i feel unsafe with her alone, when my baby was two days old he wanted to take her out to show one of his friends, we did not have base with the car seat in my house, after i told him this he said "we could just wrap her up in blankets and you can hold her, ill drive slow" and wanted to take her without the car seat, i have a witness for when this was said. (keep in mind this was in december) his car is also very messy and cluttered and does not have brakes that work properly, also when her umbilical cord was still in healing and needed rubbing alcohol to dry it out we didnt have any in my house, he suggested nail polish remover because it has alcohol in it. his home also has two very large dogs that can jump about five feet high and is very cold. He is wanting to file for a temporary custody and i am so scared the judge will not hear me out, i feel she is much safer with me and want to do what is best for her. can anyone help me and tell me what i can do to save her from this.