In this video, This Old House host Kevin O'Connor discovers the proper way to install ceiling-mounted light fixtures.
1. Turn off the electrical power to the circuit you will be working on.
2. Remove the wall switches from an existing two-gang box; be sure to label the wires for reinstallation later.
3. Push the existing electrical cables through the rear of the box.
4. Hold a new three-gang switch box over the old two-gang box and trace its outline onto the wall.
5. Use a drywall saw to enlarge the hole in the wall for the three-gang box.
6. Pry the old two-gang box from the wall.
7. From the attic, drill a hole down through top wall plate directly above the switch-box hole.
8. Feed a fish tape down the hole and into the new switch-box hole.
9. Use the fish tape to pull a new nonmetallic electrical cable up from the hole and into the attic.
10. Feed all the wires through the rear of the new electrical box, then screw the box to the wall stud.
11. Reconnect the old switches, using pigtail wires to connect the new dimmer switch.
12. Place strips of masking tape on the countertop to indicate where you want the pendant fixtures to shine light.
13. Transfer these points from the countertop to the ceiling using a plumb bob.
14. Drill pilot holes through ceiling at each plumb bob mark.
15. Cut holes for pancake electrical boxes in the ceiling using a drill fitted with an electrical-box hole saw.
16. Screw pancake boxes to ceiling joists.
17. Seal hole in top wall plate with fireproof caulk.
18. Run electrical cable from the switch box to the first pancake box, and then run another length of cable from the first box to the second, and from the second box to the third.
19. Make the wire connections at each box, using twist-on wire connectors to join white to white, black to black, bare copper ground to bare copper ground.
20. Fasten the canopies to the pancake boxes, then turn on the power and test the dimmer switch.