Looking for a per diem job in a office/clinic, where to start??

I currently work full time (3 days a week) in an SICU. It's impossible to get over time, so I want a per diem job or even 2 days a week if it's only 8hrs, but I'd rather do something a little easier, like a clinic or office. But I have no idea where to look! Searching online yields mostly agency jobs, which I don't want. Any ideas where to look? Or do I just have to find places and call them asking if they're hiring?