I don't want him to get placement of my son what do I do

If the child was born out of wedlock, in Wisconsin, first, he has to be establsihed as the biological father in a paterntiy case. I am going to assume that has been done. If not, he has no legal rights to the child whatsoever. If paternity is established I would need to know if there are any current custody or placement orders already in effect, which your post doesn't indiciate. The reason that is important is there ia bar in  Wisconsin that prevents a party from coming back into court for two years after the initial orders were entered to request a modification of custody or placement, unless the child in question is in immiment harm or danger. After the two years, the burden is less, but there is a presumption things should be left as is, and there still must be a substantial and compelling reason for the change, If these are initial orders being set, from your description of things, I would say his chances are not very good to get equal placement. How is he going to be able to take care of the child while he is away at work from 11 pm to 7 am in the morning? The schedule should be arranged in away that he has placement of the child on his off days from work to enable him to spend the most amount of time with the child on days that he is not working third shift. No one can offer you any guarantees or promises that if he pursues 50/50 placement that the court may not award him that, but from your limited fact pattern, I would say his chances are probably not good. You are well advised to find a family lawyer of your choice to find out what type of case they think you have, how long such a battle will take in court and what the cost may be to you.