I am a nonexempt hourly employee for a small company. I work 40 hours a week in the office, and am "on-call" every evening and weekends. By "on-call" I mean that I carry a pager, and answer office calls when the office is closed. Sometimes the calls only take a minute, but other times they can take hours to resolve. I am not compensated in any way for these times. I was wondering if anyone knew the legality of this issue or have any information, I feel like I am getting a bad deal.
Thanks for any help.

You need to be paid for any time you are actually responding to a call. You almost certainly do not need to be paid for carrying the pager if you are not called in.