Very hard if you want to be legal. You really can only go through an agent. We used one called Laundry Maid. Who organised a part time cleaner to come in twice a week.
It is definitely easier if you want to do it illegally (ie wait until another persons helper asks if you need help) but consequences can be dire for helper, yourself and employer.
Laundry maid were fine, but we worked it out that the two times a week for 5 hours cost us the same as a live in helper. I do not mind as I do not want someone living with me. They were efficient. There are a few other ones out there like Maids on Wheels etc. I only have experience with Laundry Maid though. They were a bit haphazard and changed the maid three times in 4 months but they were no fuss and did a good job. You pay by the month a set fee.
You could advertise but where? Of ask at the guard house at your
condo - they will often have a good idea of who is coming in as cleaners etc and may be able to put you in contact with someone (probably their niece or sister!).
Good luck
