Light switches are one of the most reliable components of any lighting circuit. Because they’re so basic, there’s so little that can go wrong with them.
This also means that they tend to last for many years – often at least 20 – before anything starts to go wrong.
But that doesn’t mean that you can take them lightly if you start noticing a problem.
Any neglected electrical component could become a serious hazard if it develops a fault and is ignored.
Usually, a broken or failing light switch isn’t a fire hazard itself, but it can overheat if the contacts or the switch wear down. Sometimes a bad light switch can cause other components on the circuit, such as a bulb, to become a fire hazard by causing an intermittent current.
Let’s look in a bit more detail at:
- Which parts of a switch can cause a fire
- Whether arcing light switches are fire hazards
- Whether you need to replace switches with common problems
What Parts Of The Switch Are Likely To Cause Fire?
There are very few parts that make up a light switch. Let’s run through them.
First, there’s the switch itself – this is the toggle you will interact with.
It’s usually made from plastic or an insulated metal that comes into zero contact with any current.
Then there’s the plate. The other part of the switch you see is the visible housing around the switch.
Again, this will be made from plastic or metal, but it’s perfectly safe. Neither the switch itself nor the plate can cause a fire.
So, the parts that could catch fire are inside the switch. There are two candidates – the wires within the actual switch or the connectors which link the switch up to the rest of the circuit.
Over time, wires will degrade, which causes them to become a little more loose, especially around the connection.
This can increase contact resistance which causes more current to build up, generating a lot more heat than the parts are designed to withstand.
This heat could cause a fire, but it’s very rare.
Even if it does, most home lighting circuits installed by a reliable electrician will use metal boxes that will contain the fire in the local area of the switch, so it won’t cause your entire home to burn down. It’ll just burn through the components.
Is Arcing Light Switch A Fire Hazard?
If you can see an arc of electricity when you flick the switch, that’s usually a bad sign.
Arcs occur when the wires aren’t entirely touching but close enough for the current to jump. An arc generates heat, which could be a fire hazard.
Small arcs or sparks sometimes happen just when the switch is being flicked off, as the current makes the last jump between the contacts before the wires are far apart.
If the spark is tiny, and there’s no further sign of problems, it can be acceptable to leave it alone.
Sometimes, arcing happens either because the contacts are worn out within the switch. So they aren’t properly connecting or because the switch itself is worn out.
When that happens, it may mean that the contacts move slower if you flick the switch slowly instead of snapping open or closed.
This can cause the contacts to hover close, creating an arc.
Whether it’s the switch or the contacts that have worn out, they normally wouldn’t be repairable, at least not in a cost-effective way.
It’s much simpler to just replace the whole switch since this guarantees a long lifespan, and they’re relatively cheap.
One more potential cause of arcing that is repairable but isn’t too common is when the wires have loosened.
This is more likely to cause a constant intermittent arc, rather than only when you interact with the switch.
Try switching off the power circuit and tightening the connections where the switch is wired into the circuit – this might resolve the problem. Still, it’s more likely the switch is at fault.
Can Sparking Switch Be Fixed?
If the switch is sparking in a way considered ‘normal’ just when it is flicked off, creating a tiny spark, then it’s not something to worry about.
It’s just how the electricity jumps between the contacts. Of course, you may stop if you replace the switch with one that snaps apart cleaner, but that’s up to you.
For sparks caused by more serious arcing problems, usually, the solution can’t be repaired, and it just makes sense to replace the whole switch.
It’s simpler and with good quality light switches, not costing a lot. It just means you get a newer switch that is definitely fixed and will last you for a long time.
Should I Replace The Switch That Makes Crackling Noise And Light Flickering?
Your light bulbs are designed to generate light with a constant current. So when the light switch is on, they glow, and when it is off, they switch off. Simple enough.
However, suppose your light switch develops a fault. In that case, it could mean that the contacts aren’t opening fully, or there’s a loose connection, which creates an intermittent current as it arcs between the contacts depending on whether it can reach or not.
This causes that crackling noise, and it’ll also mean that your light bulb begins to flicker, as it is receiving a stop-start current from the power source.
Not only is the arcing an issue at the switch itself, but this also makes the bulb more dangerous.
Bulbs aren’t designed to withstand turning on and off constantly, and the constantly-changing current could overheat the bulb.
Now you have two potential fire hazards – the switch itself and the bulb it is powering.
So yes, if you have a light switch that is causing a crackling noise and making your lights flicker, switch it off and replace the switch.
If there’s no crackling noise, but the bulb is flickering, then it might be another issue. Try different bulbs, including switching to incandescent if your LED bulbs are flickering.
If the problem persists, it’s either the switch or a more serious problem with your lighting circuit.
Final Words
Light switches last a long time. So even when they fail, they usually just stop working rather than becoming a potential fire hazard.
That doesn’t mean you can take them lightly, and sometimes they may cause issues that means you need to stop using them and replace them immediately.
Look for any tell-tale signs that your switch has a problem – is it not working perfectly every time you flick the switch? Does it feel warm?
Can you hear crackling or see a spark when it’s being switched on or off?
Suppose you ever see smoke or scorch marks. In that case, you’re already past the fire stage, and you need to shut the power off immediately and get a professional to look at the damage.
Have you ever had problems with sparking or smoking light switches?