Make-up mirrors usually have more than one light bulb above the mirror. One light bulb would cast shadows at an angle to the face, but multiple bulbs spread the light and illuminate the face from all sides. Wiring multiple bulbs on a make-up mirror is a simple procedure that can be done in half an hour or less. The bulbs are wired in series, meaning they are wired one right after the other through the circuit.
Place the electrical sockets of the mirror in front of you on a work table or desk. If a decorative box covers the light bulb sockets for the mirror, as many vanity make-up mirrors do, unscrew the box to gain access to the sockets.
Loosen the screws on the sides of the light bulb sockets. Each socket has two parallel screws sticking out perpendicular to the socket itself. These screws provide the leads to connect the circuit.
Cut a strand of 12-gauge wire about 6 inches long. Strip away about half an inch from one end and insert this end below the outermost screw on the socket on the outside position relative to the other sockets.
Wrap the bare wire around the neck of the screw and tighten the head of the screw against the bare wire. Cut another strip of 12-gauge wire long enough to have both ends clamped to two separate sockets, probably about 6 inches. Strip about half an inch of insulation off both ends of the wire, and wrap and clamp one end to the empty screw from the socket you've already begun to wire. Wrap and clamp the other end of the wire to the closest screw on the next socket. Repeat this process until all the screws are wired except for one at the very end of the series.
Cut a longer strand of wire, about a foot. Wrap and clamp this one against the last screw remaining. Let the other end of the wire dangle for a moment. Take your lamp cord and strip away the outer sheath, revealing the two insulated wires inside. Strip away about an inch of insulation from these wires.
Place the bare wire from the red-insulated wire against the bare wire from the dangling strand, and with your finger wrap the wires around each other. Screw a wire nut over them. Repeat this process for the black-insulated wire from the lamp cord and the other dangling wire, which should be the very first wire you connected to the first socket. Wrap electrical tape over any bare spots you left over from stripping too much wire away. Insert your bulbs and plug in the circuit to the wall.
Do not wire the sockets with your lamp cord plugged into the wall.