# Light Switches > Upgrade your walls with the right switches and dimmers. Understand single-pole vs 3-way wiring, trailing-edge vs leading-edge dimmers, and which switches are compatible with your LED bulbs. **Source:** The number one reason LED bulbs flicker, buzz, or won't dim properly has nothing to do with the bulb - 99% of the time it's the wrong dimmer switch. Most homes still have dimmers designed for 60W incandescent bulbs. Put a 9W LED on that same dimmer and you get a light that strobes, hums, or only dims to 40% before shutting off entirely. The fix sounds simple, buy an LED-compatible dimmer, but then you discover there are trailing-edge, leading-edge, and universal types. Some need a neutral wire your 1960s house doesn't have. Some work with 3-way setups, some don't. And if you want smart control, you're adding Wi-Fi, Zigbee, and Matter into the mix. I've mapped out which dimmers work with which bulbs, and explained the wiring that actually matters. If you've ever stood in a hardware store aisle confused by 40 identical-looking switches, this section is for you. ## Switch & Dimmer Guides - [Dimmer Switch Turns On But Doesn’t Dim: Troubleshooting Quiz](https://ledlightinginfo.com/light-switches/dimmer-switch-doesnt-dim.md) — Your dimmer powers the lights at full brightness, but move the slider and nothing changes — that's not a wiring failure, it's usually your LED bulb and dimmer speaking different electrical languages. - [Do Light Switches Need To Be Grounded? Requirement Checker](https://ledlightinginfo.com/light-switches/do-light-switches-need-to-be-grounded.md) — That green ground screw on your switch does nothing if no wire is connected to it — leaving a metal faceplate one loose wire away from full line voltage. - [Do Smart Light Switches Save Money?](https://ledlightinginfo.com/light-switches/do-smart-light-switches-save-money.md) — A single smart switch at $25–$50 can make five or six bulbs "smart" for less than the cost of one smart bulb each — but only if your switch box has a neutral wire. - [How To Install A Dimmer Switch?](https://ledlightinginfo.com/light-switches/install-a-dimmer-switch.md) — Two wires in a switch box often means both are hot — the standard switch-loop wiring in homes built before 2011. Knowing which is line and which is load before you touch anything is what keeps the install safe. - [How Often Should Light Switches Be Replaced?](https://ledlightinginfo.com/light-switches/how-often-should-light-switches-be-replaced.md) — Your light switch is only under real stress for the fraction of a second it takes to flick — which explains why a good toggle can last 40 years without issue. - [Why Are LED Dimmer Switches So Expensive?](https://ledlightinginfo.com/light-switches/why-are-led-dimmer-switches-so-expensive.md) — A basic toggle switch is a single mechanical contact — pennies in parts. An LED dimmer packs a TRIAC, a DIAC, timing capacitors, and an LC filter behind that same wall plate. - [Do Dimmer Switches Get Hot?](https://ledlightinginfo.com/light-switches/do-dimmer-switches-get-hot.md) — Modern dimmer switches run hottest at near-full brightness — not dimmed low. That's the opposite of how older rheostat dimmers behaved, and it changes how you diagnose an overheating switch. - [How Do Wireless Light Switches Work?](https://ledlightinginfo.com/light-switches/how-do-wireless-light-switches-work.md) — A wireless light switch is actually two separate devices — a receiver wired into your lighting circuit, and a transmitter that can go anywhere. The button on your wall has never been the switch; now it just doesn't pretend to be. - [Is Leaving A Light Switch In The Middle Safe?](https://ledlightinginfo.com/light-switches/leaving-a-light-switch-in-the-middle.md) — A light switch left "in the middle" isn't actually in the middle — the snap-action spring inside forces the contacts fully on or off regardless of where the toggle sits. The danger only starts when that spring wears out. - [Can You Have A Dimmer Switch In The Bathroom?](https://ledlightinginfo.com/light-switches/dimmer-switch-in-the-bathroom.md) — Under NEC 404.4, a bathroom dimmer is legal — but in a UK bathroom, BS 7671 zones often push the switch out of the room entirely. That's not a workaround; it's the safest option regardless of where you live. - [Can A Dimmer Switch Cause A Breaker To Trip?](https://ledlightinginfo.com/light-switches/dimmer-switch-trip-a-breaker.md) — Random trips and instant trips look the same from across the room, but they point to completely different faults — and fixing the wrong one won't stop the tripping. - [Does A Dimmer Switch Control Amps Or Volts?](https://ledlightinginfo.com/light-switches/switch-control-amps-or-volts.md) — Your dimmer never touches the peak voltage or amps — it just bites a chunk out of each AC half-cycle, leaving the circuit rating intact while shrinking the energy that reaches the bulb. - [Are There Fuses In Dimmer Switches?](https://ledlightinginfo.com/light-switches/are-there-fuses-in-dimmer-switches.md) — Older dimmers did have fuses — soldered directly onto the board, never designed to be swapped out. When one blew, you replaced the whole dimmer anyway. - [Is A Bad Light Switch A Fire Hazard?](https://ledlightinginfo.com/light-switches/is-a-bad-light-switch-a-fire-hazard.md) — A switch plate that's warm to the touch isn't just annoying — it's a high-resistance connection converting your wiring into a localized heater. That heat is the first step toward a real fire risk. - [Can You Put A Dimmer Switch On Fluorescent Lights?](https://ledlightinginfo.com/light-switches/dimmer-switch-with-fluorescent-lights.md) — Your fluorescent lamp cuts out while the dimmer dial still has a quarter of its travel left — that's the dead zone, and it's not a wiring fault. It's the ballast hitting its minimum load threshold before the slider bottoms out. - [Why Is My Dimmer Switch Upside Down?](https://ledlightinginfo.com/light-switches/dimmer-switch-upside-down.md) — Under NEC 404.7, an upside-down single-pole dimmer is a code violation — but the fix is usually just rotating the device 180° before touching a single wire. - [What Does A 2-Way Dimmer Switch Mean?](https://ledlightinginfo.com/light-switches/2-way-dimmer.md) — A UK '2-way' dimmer and a US '3-way' dimmer are the exact same hardware — different continents, different label. Order by terminal count instead and you'll always get the right switch. - [Can Dimmer Switch Be Used On A Ceiling Fan?](https://ledlightinginfo.com/light-switches/can-dimmer-switch-be-used-on-a-ceiling-fan.md) — A phase-cut dimmer quietly cooking a ceiling fan motor is a documented fire hazard — and the wiring failure that causes it has nothing to do with too much voltage. - [How Many Dimmer Switches Can Be On One Circuit?](https://ledlightinginfo.com/light-switches/dimmer-switches-on-one-circuit.md) — Wire two standard 3-way dimmers to the same fixture and they'll clash — each chopping the AC on its own timing, producing flicker, buzzing, or bulb damage. That's exactly why a master/companion pair exists. - [Does A Dimmer Switch Require Special Wiring?](https://ledlightinginfo.com/light-switches/dimmer-switch-wiring.md) — Swapping in an LED-rated dimmer isn't enough on its own — the bulb itself also needs to be marked dimmable, or the dimmer has nothing to work with. - [Is Dimmer Switch Buzzing Dangerous?](https://ledlightinginfo.com/light-switches/is-dimmer-switch-buzzing-dangerous.md) — Your dimmer chops the AC waveform 120 times per second, and that faint hum is just its inductor physically vibrating — harmless. A hot faceplate or crackling sound is a different story entirely. - [How To Wire Downlights To A Switch: Simple Diagram](https://ledlightinginfo.com/light-switches/how-to-wire-downlights-to-a-switch.md) — A downlight wired with live and neutral swapped will still turn on and off — but the fitting stays at mains potential every time the switch reads off. That silent reversal is why a switched circuit can still kill you. - [How Far Should The Light Switch Be From The Door?](https://ledlightinginfo.com/light-switches/how-far-should-the-light-switch-be-from-the-door.md) — Popular articles cite an "8-inch rule" for switch placement from a door frame — but that's folklore, not code. The NEC just says "near an entrance" and leaves the rest to common sense. - [Why Do Light Switches Keep Shocking Me?](https://ledlightinginfo.com/light-switches/light-switches-keep-shocking-me.md) — That static zap from your light switch isn't the switch's fault — the 35,000 volts built up on you. Persistent tingles, warmth, or sparks are a different story entirely.