What I change on an existing circuit
The rule is simple: if something is already wired into that spot, it can usually be replaced, and most light fixture installation work is exactly that. Most calls are a fixture the previous owner chose, a bathroom bar with a burnt-out socket, or a fan that has developed a rattle.
- Chandeliers, pendants and flush mount ceiling fixtures
- Vanity bars, sconces and hallway lights
- Ceiling fans, with or without a light kit
- Trims and retrofit LED inserts in pot light housings you already have
- Dimmers, timers, motion switches and smart switches
- Under-cabinet strips that plug in or replace an existing unit
- Closet and stairwell fixtures running the wrong bulb type
Light fixture installation, step by step
Power goes off at the breaker, not at the wall switch, and the conductors are confirmed dead at the terminals with a tester. That check matters, because a switch loop can leave an unswitched hot sitting in the same box, live and looking exactly like the wire beside it. The old fixture comes down with its canopy supported, never left hanging by its own leads.
Then the box gets a proper look. Is it fastened to framing or floating in the drywall. Is there a ground wire in there. Is the plastic cracked, or the box too shallow for the splices it already holds. Conductors are stripped to the right length, joined with correctly sized wire connectors, the identified conductor goes to neutral, and the fixture ground lead lands on the ground screw in the box. Wires are folded back so nothing is pinched when the canopy seats, and every splice stays inside an accessible box, never buried behind drywall.
Ceiling fans need a box rated for them
A standard plastic or metal octagon box is made to hold a light, not a spinning weight. Fans go on a box marked as acceptable for fan support, screwed to a joist or carried on an expanding brace bar that feeds through the existing ceiling hole and locks between the joists. That brace goes in without opening the ceiling, which is why a fan swap rarely turns into drywall work.
Mounting height matters as much as the box. Blades should sit about 2.1 m (7 ft) off the floor, with room above them so air can reach the blades, and at least 45 cm (18 in) between the blade tips and the nearest wall. A flush mount suits a low basement ceiling; a downrod suits a high one. Wobble is nearly always mechanical rather than electrical, so blade screws get tightened, blade alignment is checked, and a balancing kit sorts out the rest.
Dimmers, LED bulbs and smart switches
LED lamps changed the rules for dimmers. An old dimmer built for incandescent loads will make an LED buzz, flicker, drop out at the bottom of the slider or refuse to switch off completely. The fix is a dimmer rated for LED loads, matched to bulbs that are genuinely dimmable, with the low-end trim adjusted while your own bulbs are in the fixture rather than a test lamp.
Smart switches add a second requirement: most of them need a neutral in the switch box, and many older Toronto switch boxes contain only a switch loop with no neutral present. Where that is the case, the choices are a model designed to work without a neutral alongside compatible bulbs, or an electrician to bring one in. Three-way locations need the matching companion switch from the same family, and box depth counts too, since smart switches are bulky and the wiring has to fold in behind without strain.
What goes to a licensed electrician
Some work is simply not mine to do, and saying so early costs you nothing. New circuits, new cable runs, panel and breaker work, cutting new pot light openings, aluminum branch wiring, knob and tube, boxes with no ground, brittle or scorched insulation, and any circuit that trips when the light goes on all belong to a licensed electrician. I will tell you exactly what I found so you can pass it on.
Once their part is done, mine picks up again. Light fixture installation on the circuits they have run, patching and painting the ceiling around new openings, and setting up your dimmers and smart switches afterwards are all things I can finish for you.
