What options are available to us to force our 23 year old son to move out of our house?

Well, depends on a few things.  If you ask him to leave, and he refuses, you’ll need to take civil action to get him out.  If he doesn’t pay rent (and never has nor has there been an agreement to do so) and he’s not claiming a title to the property, you’re looking to file an unlawful detainer lawsuit (basically, he’s a guest that’s overstayed his welcome).  If he’s claiming some title to the property, you’ll look to file an ejectment lawsuit.  From the facts you’ve provided, it doesn’t sound like you’re dealing with an eviction situation.  In either an unlawful detainer or ejectment action, you may find it helpful to consult and hire a real estate attorney to do this for you.  Depending on your county, you may find helpful guidance information and forms for each of these on the Clerk of Court’s website.  Word of caution - each has particular steps to be taken, and if such steps are not taken correctly, it can result in delays and perhaps a need to refile.