Will bio dad get visitation rights if hasn't seen the child since he was 1 and the child thinks another man is his father.

Your post doesn't indicate whether paternity has been established; without his doing so, he has no legal rights towards the child in any way. I just wrote a blog at our firm's web site under the family law category that discusses the law on this very issue; if under Wisconsin law, he was previously adjudicated to be the child's father, he would have the right to petition for visitation rights; you could argue that it is not in the child's best interest to do so; you can make the same argument if he first files for paternity now and advocate against DNA testing since the child was raised to believe that your current husband is the child's father. The court would have to determine if proceeding with paternity under those circumstances would be in the child's best interest; I wrote a blog about that very topic as well a few months back which you can read at our law firm's web site. You can also file a petition to terminate their parental rights, if your husband is willing to go along with you in a step-patent adoption of your child.