Legal Question in Landlord & Tenant Law in California

If he pays rent or is supposed to, then he is a tenant and you would have to or through the formal, legal eviction process. If not, order him to leave and tell him you will call the police if he does not [and to take his stuff with him]. For the time he remains there, do not feed him , let him take anything from the frig. that he did not buy, speak to him, show any affection, etc.