Things You'll Need
Hammer and chisel
Whether you are talking about an indoor or an outdoor installation, there are occasions when you need to replace outlet boxes, either due to a wall repair or just to change the color of the outlets and their boxes. When you're working with a brick wall, either the hole is already cut into the brick itself, or the brick was set around the outlet box, so replacing the box is only a matter of pulling the old one out and setting a new one in its place.
Shut off the power to the electrical box at the circuit (breaker) box for your home. Double check to ensure that the power is off by testing the leads to the receptacle in the box you are replacing with a voltage tester to avoid electrocution.
Use a screwdriver to remove the cover plate over the electrical box and receptacle. Loosen and remove the screws holding the receptacle in place. Gently pull the receptacle out of the box and use the voltage tester. Unscrew the screws on the side of the receptacle and disconnect the wires to remove the receptacle completely.
Loosen the box within its frame. Insert the chisel to one side of the box and gently pry inward. Repeat the process around the edges of the box until it breaks free of the mortar holding it in place. Slip it out.
Put on your safety glasses. Chisel the old mortar holding the box into the brick out with the hammer and chisel. Take your time to avoid damaging the wire cable stubbed out of the brick wall for the box and receptacle. Blow into the squared-out area to remove any final dust.
Mix up some mortar with your trowel. Add water to the mixture until you have a batter-like consistency. Smear it around the entire perimeter of your cut-out in the brick, as well as the back wall. Add extra mortar to ensure there is plenty.
Slot the wire through the hole in the new outlet box. Push the box into place within the brick wall, ensuring that it bonds with the surrounding mortar. Scrape off excess mortar with your trowel, allow the mortar 24 hours to dry, then rewire the receptacle, replace the cover plate and turn the power back on.
In the case of boxes that are mounted via screws into the brick, merely remove the screws to remove the box, then mount a new box in its place.