@Victoria576 I certainly wouldn't trust some stranger to do this. It's a lot of responsibility, and if they fall down on the cleaning, or the way they deal with guests, they could tank your ratings and reviews. For all you know, since you are going to be overseas, they could just allow all their friends to stay there, too.
I've had housesitters before (I know this is a little different) who were friends of friends, who managed to do tons of damage to my home in a few short weeks, didn't do any of the small chores I asked them to keep up with, took my dog out and lost her (she was found by others a few days later, hungry and confused) and they were staying for free, even.
If you don't have a friend or relative who is willing to look after things for you, or can't find anyone locally who actually does this for a living and has good references, I don't know what to suggest.