Trusted access is the seam
Residential security design concentrates on the uninvited: perimeter, detection, response. But the people most capable of enabling an incident are the invited. A housekeeper knows the family's rhythm better than any surveillant could learn it. A driver holds the schedule, the routes, and the school run. A contractor's crew has seen the interior layout, the safe room, and the camera positions. None of this requires anyone to be malicious. Information that concentrated will leak through carelessness, through social pressure, through a bad hire three layers down at a vendor the family never met.
The pattern in residential incidents across sectors is consistent: some element of inside knowledge, orientation, timing, or access, shortened the attacker's work. The question a protective program has to answer is not whether the household staff is trustworthy. Most are. It is whether the household would notice when one person, once, is not.