Why does the bathroom light fixture over the tub make a clicking noise when lights get turned off after taking a separate shower?

Answer 1

Spiders like nice warm and damp places to make their nests - so a bathroom light fixture is one of their favourite places - and they don't seem to care if one of the places they use to fix one of their webs or a nest is a pair of live and neutral electrical terminals! If the light fixture is of an old type that has exposed terminals then a damp spider's web or nest can easily become a conducting circuit between the live (hot) and the neutral or earth (ground) wires. In older houses where open coal or wood fires are (or were) used, the damp web or nest gets covered in soot from the air. This is even more likely if the bathroom ceiling is just under the loft or attic of the house because, even if the roof is watertight, soot can often drift into the loft through gaps in the roof tiles. (A bit like snow sometimes does.) Then, because soot is carbon, which is a very good conductor, the current may sometimes grow to a point that the web or nest catches fire! If that happens the circuit breaker may or may not trip to shut off the current and the fire often goes out without causing much damage. You might just put the circuit breaker back on and wonder why it went off because no light bulb has died! Then, if the spider is still alive, 'cos it was away hunting at the time - or another spider comes along - the whole process starts over again... Usually these damp webs or nests don't actually catch fire, they just dry out. But whilst they are still damp you can sometimes hear a clicking noise from little sparks that jump from the web to the live supply terminal or, sometimes, to a tiny exposed bit of bare live cable going into the terminal even if that terminal itself is not affected by the web or nest. This can happen particularly if the web or nest starts from a bare length of ground wire, the kind which is quite commonly left uninsulated in old wiring. Eventually, when the nest or web has dried out because the bathroom is no longer so steamy, the clicking stops. Next time someone takes a nice long shower the web or nest gets damp again and the whole cycle repeats! So, to be sure they are clear of spider's webs or nests and will not become fire hazards (now or in the future) the bathroom and kitchen light fittings in any house should be checked every five years so that any such debris can be removed. Experienced electricians know all about this phenomenon, certainly in Europe, where the lights are supplied at 230 Volts and this kind of fault may well be much more common than in 120 Volt areas. So, if this kind of fault has to be fixed, or the breaker for the lights keeps tripping for apparently no reason, any experienced "old timer" electrician will always check the mains supply wiring and terminals in the bathroom and kitchen lights first. IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

If you do this work yourself, always turn off the powerat the breaker box/fuse panel BEFORE you attempt to do any work AND always use a meter or voltage indicator to insure the circuit is, in fact, de-energized.

Answer 2

The clicking noise could be caused by the metal of the light fixture expanding and contracting as it heats up and cools down from the shower. This is a common occurrence for metal fixtures and usually not a cause for concern.