have you tried talking with the states attorney?
I know this is a civil matter but, if, you are arwarded the house, seems to me, he's an unwanted guest.
I'd at least call the states attorney to find out where you stand.
Not sure what 2 years has to do with anything
Smoking pot is against the law in most of the 50 states.
Your kids deserve better then to have to be around some one smoking pot in the house?
Do you know where, he's hiding his stash? You have the option of telling the police on him.
Law abiding citizens do have rights in the U.S.
Wish you all the best