Sorry for the late response, hope you come back. Well, since it's your mother's house, it is your mother who must ask him to leave. I'm not sure if she doesn't have to give him notice if he's got his mail coming to the house. The way to get around that though, is to tell him that the police will be called when he's using. Then , there needs to be follow through. Maybe locks have to be taken off the doors, to get it done. The only thing a family can do under these circumstances is to have an Intervention and tell the addict that until he tests clean and sober, they will have nothing to do with them. Change the locks, and call the police if he returns. I do hope your mother is aware of the gravity of the situation., that right now she's enabling him to kill himself in her home. She is not doing him any favors and in fact, if he does get clean and sober he will forever resent her for letting it go on with her not stopping him in her home, at least. I think you and your mom need to talk to an Addictions Therapist, so that your mom will understand that she is directly harming her son by letting him to continue using in her house. I think she needs this type of support in order to act in his (and yours) best interests. Please come back and let us know what you think?