Husband walked out 4 years ago, haven't heard from him, don't know where he is, how do i file for divorce?

If you want to file for divorce, you will need to do the research to learn how to do this. The Tennessee Supreme Court has attempted to assist people in filing for a divorce when there is an agreement. Go to their website and review their paperwork. Look online and after all the research that you feel comfortable doing you believe you can do it on your own, you are entitled to represent yourself. You can often find very good information on the internet....the hard part is that the really bad advice often is indistinguishable from the good. I tell people all the time that I am entitled to plumb my own house....but it isn't what I do everyday. I am not going to do as good a job as an expert. Additionally, there are often issues that people have not even considered that need to be addressed. Sometimes the best answer to a problem is to hire a professional. If your car has a flat, don't simply look for the cheapest tire and try to put it on the rim yourself. I strongly urge you to hire a good lawyer and get this done correctly.