The Service May Send Someone Else
You may need to schedule maid service while you're out or at work. In theory, it's a great concept. When you get home, the house will be spotless, as if by magic. Once you hand over the key, though, you don't really know who will be stopping by. Some services assign specific workers to accounts, but that's not a guarantee that the same person will always clean your home. Employee turnover, illness and scheduling conflicts could result in a number of different people cleaning your home in any given month, some of them strangers to you. Quite a few cleaning services subcontract labor, too, giving them less control over employee screening and work quality. Not to put too fine a point on this, but the idea of having a spare key to your house just floating around out there should really make you think twice about the potential security problems.