Household workers include anyone who does work in or around your home such as babysitters, nannies, health aides, private nurses, maids, caretakers, yard workers, and similar domestic workers. In addition, the worker must be your employee, which means you can control not only what work is done, but how it is done.
It does not matter whether the work is full-time or part time, or that you hired the worker through an agency. On the other hand, if only the worker can control how the work is done, the worker is not your employee, but is self-employed.