I know in NYS, if you give domicile to anyone for more than 30 days in your house and they don’t leave after being asked, you have to do a formal eviction.
Rent or living there free is not a consideration.
I went down that road with an alcoholic girlfriend.
If you just put their stuff at the curb and lock them out, a cop will show up at your door instructing you to let them back in.
I knew a guy who had that problem. HE moved out.
And this story is why you never want to sublet a room in your house.