Are you already a licensed RN or a nursing student? I know I've done clinicals in a couple of places that apparently use either part-time or prn staff as these nurses also work in other facilities around town.
As far as being a nursing student, we have many in our class who work as techs, secretaries, etc. for hospitals around town and most are VERY flexible with their schedules (including my facility).
Most of the hospitals have great online listings indicating work hours required; I'd jump on and check them out or call their nursing recruiters directly.