Your fireplace mantle is a popular place in the home to decorate, either with lights during the holidays, or with the permanent placement of a TV. Any electrical item will of course need an outlet to maintain power. If you want to add an outlet by your fireplace, there are some precautionary measures. Anytime there are wires around heat, you will need to be extremely careful to keep your family and home safe. Always consult a licensed electrician to safety work with electricity.
When deciding to add an outlet around a fireplace, you will want to consider the wiring behind the fireplace. The wiring should always be installed with the environmental conditions in mind in order to protect the wiring and maintain the integrity of the electrical circuit. Also, you will have to double-check that all ground wires will have to be bonded to protect all of the circuit devices.
Once you inspect all of the safety issues you may be able to add an outlet. There is high temperature rated electrical wiring is available for applications such as this that you will be able to find at a hardware store. Also, I would recommend inquiring heat resistant wiring may be required to be installed in a protective conduit and a metal outlet box.