Section 1954 works as a closed list. Subdivision (a) says a landlord may enter "only" in the enumerated cases: an emergency, to make necessary or agreed repairs, decorations, alterations or improvements or supply agreed services, to show the unit to prospective or actual purchasers, mortgagees, tenants, workers or contractors, to make the pre-move-out inspection under § 1950.5(f), where the tenant has abandoned or surrendered the premises, under court order, and for two specific statutory schemes. Anything outside that list is not authorised by the section, however routine the landlord considers it.
Subdivision (d) supplies the procedure. The landlord must give reasonable written notice stating the date, approximate time and purpose, and enter only during normal business hours. Twenty-four hours is presumed reasonable in the absence of evidence to the contrary, and mailing at least six days ahead is presumed reasonable. There are two carve-outs: showings to prospective or actual purchasers may be noticed orally, in person or by telephone, but only where the landlord has told the tenant in writing within the last 120 days that the property is for sale and that oral contact may follow, and written evidence of the entry must be left inside the unit; and the tenant and landlord may agree orally to an entry for agreed repairs or services within one week.
Subdivision (e) removes the notice requirement for an emergency, where the tenant is present and consents at the time, and after abandonment or surrender. And subdivision (c) is the sentence that catches the pattern rather than the single visit: the landlord "may not abuse the right of access or use it to harass the tenant". Two other sections lean on this one — § 1953 makes a lease clause waiving § 1954 rights void, and § 1940.2 treats a significant and intentional violation of § 1954 as unlawful conduct when done to make a tenant leave. Whether a given entry was an emergency, or whether repeated lawful-looking entries amount to abuse, is a factual question worth taking to a lawyer or a tenant service.