Do you know what kind of electrical panel you have? If your home is built between 1950 and 1990, you may have a panel made by Federal Pacific. These are very unsafe and should be replaced immediately.
The details are here… http://www.angieslist.com/articles/your-federal-pacific-circuit-breaker-panel-safe.htm
If you do have this type of panel, please contact my master electrician and he can replace it for you.
Rob Sharp, Master Electrician