I am divorced and my ex husband refuses to leave. I hae repeatedly asked him to move out but he refuses to go. How can I evict him?

I am in the US

Did you get the house in the divorce? If so then you would have to do a formal eviction. You can start with giving him a letter stating that he needs to be out in "x" days (that depends on the state). If he does not want to leave after that then you have to go to court.

The small claims or magistrate court should have information about evictions; sounds like he needs counseling of some sort.

Yes I own the house everything is in my name. The only problem is he is receiving mail at my mail box and listing my property as his address. Does this letter have to be a formal letter from a Lawyer or can I write a letter and give him a copy?

First, this post needs combined with the other one you can just add on information at the bottom. Second, you can do the letter as long as you are capable of typing up a formal one.

I've merged your two posts, please don't start a new thread with a follow-up question as it can be confusing.

You have to go through a formal eviction process appropriate for your area. Go to your local housing court and ask what the process is.