Legal Question in Real Estate Law in California

Civil Code section 1954 specifies when and under what conditions a landlord may enter the tenant's premises. The landlord may enter in an emergency, or, upon reasonable prior notice, for a short list of other reasons including inspection and repair. Twenty-four hours advance written notice is rebuttably presumed "reasonable notice," but in unusual circumstances a longer or shorter notice period may be permitted or required. The new owner would be the landlord as meant in the law.

After a leased property is sold at foreclosure, the lease is wiped out UNLESS it was senior to the foreclosed lien, which is pretty rare, and the former tenant is now a holdover tenant, one step above a trespasser, but is entitled to the full notice and formal eviction (unlawful detainer suit, etc.) processes given to tenants in general.

You have a right to evict, use it, and don't play games that could get you in legal trouble by trying to force your way into their home.