How do you get your adult child to leave your home that is considered their primary residence?

[jocheved]

Take all their mail and return to sender, throw their stuff out the door, then hire 5 burly bikers to give him an offer he can't refuse.

[gabrielo19]

Sell the house and move somewhere else but don't tell him where.

[naseem]

then serve them with an eviction notice. whats the problem?

[hackett]

You need to send them a certified eviction notice to his permanent residence, i.e. your house. Legally you cannot evict a spouse or underage child. You do not have this problem. If their "chaos" has been damaging, you may be offered recourse from the tortfeasor (your child causing you damage). But in that instance you will have the burden to prove damages (example what have they deprived you of in terms of life, liberty, and/or property).

Tenant Law:
(2) Any such provider who seeks the eviction of an occupant shall provide to the occupant and to the department written notice of the grounds of the proposed eviction, including reasons, relevant facts and the sources of those facts. The notice shall contain a reference to this section and shall advise the occupant that he has the right to a hearing, to be represented at such hearing by a lawyer or other person of his own choosing. At the request of the occupant, the provider shall afford the occupant, or his representative, reasonable access to review and copy his file before the hearing, including any document intended to be used against him at the hearing.

(4) The provider shall have the burden of proving, by a preponderance of evidence, the propriety of the proposed eviction, but all such evidence shall be within the scope of the reasons for eviction set forth in the notice required by paragraph (2). An eviction under this section shall be deemed proper if the occupant has substantially violated an essential provision of a written agreement containing the conditions of occupancy or if the occupant is likely, in spite of reasonable accommodation, to impair the emotional or physical well being of other occupants, program staff or neighbors.

You may run in to a problem with the fact he was a child and is now an adult, in your house, therefore never fully entering into a lease. You probably should consult someone who is a real estate attorney in your state to clarify the laws.