My nephew has been living with us since he was 14 under a guardianship approved by the Michigan circuit court. He is now 18. He refuses to live by the house rules, I have found drugs and drug paraphanalia in his room. He is drinking and staying out all night. The guardianship automatically terminated when he turned 18. If I tell him to leave and he refuses, is it considered trespassing and can I call the police to have him removed? If not, do I have to go through the eviction process? We have not charged him rent and do not have any kind of lease agreement. Thanks for any help you can provide.