After the installation is complete, cover the notch with a metal shield, available in the electrical section of home stores. Repair the wall over the shield and the hole in the ceiling to finish.
If permitted, new electrical wiring may be run behind baseboards to serve a new wall receptacle, or to a switch and new ceiling light fixture. To pass the cable through the wall studs a notch is cut in the wood and a metal shield, sometimes called a nail guard, is fastened over the notch to protect the new wires from nail and screw punctures.
Mark and cut a hole about 4 inches wide in the wall to expose the top plate and a few inches of the wall cavity. Also cut a few inches into the ceiling to allow for reaching in to grab the fish tape.
At the floor the wallboard is cut to allow for boring a hole in the soleplate. Then the run can be made from an upper floor to the room below or vice versa.