It is always best to call a certified electrican when you need any electrical upgrades or install done in your home or business, however cities and towns do allow homeowners to do their own work with inspection after completion. Some homeowners have the knowledge and are comfortable working on certain electrical items in their house, however if you see some of these key issues in your house while doing electrical work it is time to call a certified electrician.
Melted or discoloured wires or boxes.
Breakers are tripping or not turning back on once your upgrade or installed.
Flickering or receptacles working off and on.
Warm devices (this can be because of an overloaded circuit but not enough to trip a breaker).
Zaps or electricution when touching a device.
If any of these are present when doing your own work it is time to call a professional! Remember the safety of you and your family isn't worth saving a few dollars.