3 answers
★ Best answer
The click itself isn't always a sign of failure - sometimes it's just the contacts making noise as they wear. I had a switch in my old house that clicked like crazy for years before I finally replaced it, and when I opened it up, the actual mechanism was fine, but the metal contact points had developed a slight gap that made them clap together instead of sliding smoothly.
The toggle itself probably has wear in the pivot point where it connects to the mechanism inside, which lets it move around more than it should.
Over time that internal spring and contact get loose too, so you get that weird play and clicking sound instead of a solid click. Replacing the whole switch is cheap and takes two minutes - just kill the breaker first and swap out the old one.
If it's an older house the wiring might be fine, but those switches don't last forever.
Loose switches can actually be a fire hazard if the internal contacts are arcing, so don't assume it's harmless just because it's been clicking for years - replace it sooner rather than later. The real culprit is usually the mounting screws that hold the switch body to the electrical box working themselves loose from vibration, which is a quick fix before you move on to considering whether the internal mechanism itself has actually failed.
Your answer
Log into answer.