I think my approach in such a situation would be:
- Find a family counselor that all 3 of you could meet with. Have them help you work through these issues.
- Set a date for him to move out. Your wife needs to be on board, and you need to be prepared to remove him if he won't go willingly. Be prepared to change locks, have a police officer present, etc.
Some people won't take responsibility for their lives until they're forced to.