I tried to help a younger guy I worked with for a while - let him be a
room mate. Family is the cops - I couldn't do anything to him without a leagal 30 day notice even though he never paid rent. As family said if someone sees his vehicle at your door more than 7 times a month and has a toothbrush you can not get the cops involved. Turns out he was a little user and knews this.
So I got a mutual friend to come over and give him the reason that he didn't want to be there anyomore. He was gone in a day.

If you do give notice get it notorized so no question when that day is.