Burning smell coming out of my wall.

There is a burning tuna like smell coming out of my bedroom light switch. A little smoke is coming out. When I leave the light off everything is okay. This has happened before three years ago and I got a friend to replace the light switch, and everything was fine. It’s not alarming me as much as it did before, but I’m scared the house might burn down while I’m asleep. What is the problem going on? Any amateur electricians know what’s happening? I’m leaving the light off for now. The house is 80 years old.

I’m not an amateur electrician, I’m an electrical engineer, and my professional opinion is that you need to have this checked out by a qualified electrician. It could be something as simple as your friend didn’t tighten the connections enough when he installed the switch, or it could be something much more serious like an overloaded circuit and possibly an undersized breaker/fuse.

Since the worst case scenario is that you do burn your house down, this is fairly serious and needs attention ASAP. Call an electrician NOW.

Could one of the tuna just have been caught swimming against the current?

I’ll second that. Turn the switch off. If the light is on the ceiling, then remove the bulb, then call an electrician.

As another electrical engineer AND a volunteer fireman, I’ll second this. Hell, I’ll third, fourth, and fifth it.

Shouldn’t the OP turn the whole circuit off at the fuse box?

Time for a convenient electrical fire and have the insurance build you a new home.

That would certainly be my inclination even if the burning smell goes away when the switch is off.

If the problem has come back, there’s a possibility that insulation on a wire has been stripped off (for example, by a rat or mouse chewing on it) and is contacting something in the wall like insulation or a support beam.

Even if the problem appears to be right at the switch, having a professional look at it promptly is a necessity.

Yes. It’s very likely that it’s arking inside the switch so it doesn’t matter if it’s on or off. I’ve seen them break internally so that there is a free floating piece of metal.

That’s a job for Indiana Jones!

Damn new-builds - always shoddily constructed.

  • Colophon (England)
    BTW, seconding what everyone else says. A “fishy” smell coming from old electrics means something is getting much hotter than it ought to be - it’s the smell of insulation burning, basically.

Older wiring in my area consisted of impregnated cloth. When it gets hot it just disintegrates. However, Smoke was observed so I’m more inclined to think it’s the switch, particularly since it happened with the switch off.

And remember to tell the electrician that you had the problem three years ago, too. That way she knows to look for and eliminate the root cause .