If you need a new receptacle or a new light and switch, the usual procedure is to run cable inside walls. That is a complicated, messy job. Cutting and patching walls takes much more time than the wiring. Wall-mounted raceway wiring eliminates that trouble and is available in plastic or metal.
Planning the job
Metal raceway can be painted. Have a salesperson help you assemble all the raceway parts you need: a starter box, channel, clips, cover plates, and elbows if you need to turn a corner. You need black, white, and green wire for the length of your run. Use 14-gauge wire for a 15-amp circuit and 12-gauge for a 20-amp circuit.
About 3 hours to install two new receptacles
Drill, screwdriver, level, rubber mallet, strippers, side cutters, hacksaw, lineman's pliers
Stripping, splicing, and connecting wires to a terminal; cutting metal channel; driving screws into a wall
Spread drop cloths on the floor
Raceway components, wire nuts, electrician's tape, screws
Position a flat elbow onto the end of the raceway channel and hold it over a stud. Have someone help you hold the channel in place, and level it. Mark where to cut the channel -- when installed the channel extends into the box by about 3/8 inch. Cut the channel with a hacksaw.