How to Install Vanity Lights Above a Bathroom Mirror

Vanity lights change how your bathroom feels—good ones cast even light across your face without shadows, bad ones make you look exhausted. The fixture sits directly above the mirror, usually 24 to 30 inches wide, and wires into the electrical box that powered the old light (or a new box if you're starting fresh). Done right, it's a straight swap: kill the power, disconnect old hardware, connect new wires, mount the new fixture, and you're done. Done poorly, you'll have flickering lights, loose connections that burn out bulbs fast, or worse—a fire hazard. This guide covers the standard replacement using an existing circuit.

  1. Kill Power First. Locate your home's electrical panel and flip the breaker that controls the bathroom light to the OFF position. Test the existing vanity light switch to confirm it no longer turns on. If you don't know which breaker controls that light, flip the main breaker instead—it takes longer but it's certain. Leave a piece of tape on the breaker handle so no one switches it back on while you work.
  2. Document Before Dismounting. Unscrew or unclip the old vanity light from the wall, pulling it away gently to expose the electrical box behind it. You'll see two or three wires—black (hot), white (neutral), and possibly a bare copper or green (ground). Use a screwdriver to loosen the wire nuts holding these wires together, then untwist them by hand. Note which wire color goes where before you disconnect anything. If there's a mounting bracket bolted to the box, unscrew that too.
  3. Check Box Condition Now. Once the old fixture is removed, look inside the electrical box. It should be a metal or plastic cube recessed into the wall, with at least two cable entries (the wires coming in). Check that the box is secure and not cracked or damaged. If it's loose, tighten the screws holding it to the stud. If it's damaged or undersized for the new fixture, you'll need to replace it—call an electrician for that step.
  4. Mount Bracket Level. Remove the mounting bracket from the new vanity light and attach it to the electrical box using the provided screws. The bracket should sit flush against the wall and be level—use a level if the old fixture's hole pattern wasn't perfectly level. If the new bracket doesn't align with the old screw holes, you'll need to fill those holes with spackle once the new fixture is installed.
  5. Ground First. The bare copper or green ground wire from the electrical cable in the wall should connect to the ground wire on the new fixture (usually a bare copper pigtail attached to the bracket or fixture body). Twist these two wires together clockwise, then screw a green wire nut onto them, turning it until it's snug and won't come off if you pull on the wires. Don't overtighten—just hand-tight.
  6. White to White. The white wire from the wall should connect to the white wire from the new fixture. Hold them parallel, strip about half an inch of insulation from each if needed, twist them together clockwise until they're tight, then screw a wire nut onto them. Give each wire a gentle tug to confirm the connection won't slip.
  7. Black to Black. The black wire from the wall connects to the black wire from the new fixture using the same twisted-and-wire-nut method. This carries live power, so double-check you've flipped the breaker before you touch it. Twist, secure the wire nut, and tug-test it.
  8. Accordion Fold Wires. Gently push all three connected wire pairs back into the electrical box, arranging them so they don't bunch or pinch. The wires should sit comfortably without forcing them. This is why box size matters—too small and you can't fit everything safely. Once everything fits, hold the fixture body up to the mounting bracket to confirm the geometry works before final attachment.
  9. Fasten Fixture Straight. Align the fixture body with the mounting bracket and attach it using the provided fasteners (usually small bolts or clips). Tighten these evenly on both sides so the fixture sits flat and level against the wall. Don't overtighten—you're looking for snug, not crushing. Step back and check that it's straight before moving on.
  10. Bulbs and Diffusers On. With power still off, screw the appropriate bulbs into each socket (check the fixture's specifications for wattage and type—LED, incandescent, or halogen). If the fixture came with glass shades or diffusers, install those now. Make sure everything is hand-tight and sits evenly.
  11. Flip Switch and Verify. Go back to the electrical panel and flip the breaker back to ON. Return to the bathroom, flip the wall switch, and confirm that the light comes on and stays steady. If it flickers or doesn't light, turn it off and back on once more—a one-time flicker during startup is normal, but persistent flickering means a loose connection.
  12. Fill Holes and Paint. If the new fixture's mounting holes don't align with the old ones, fill the empty screw holes with paintable caulk or spackle. Smooth it flush with the wall, let it dry, and paint over it to match the wall color. Once dry, you're done.