If I spray a 70% alcohol mist onto a regular household light switch, is that a fire hazard? I assume not since the red and black wires would both need to be exposed and close together... But assuming there was a short circuit, would the alcohol/water just heat up and evaporate instantly without causing any real damage?

Or am I mistaken? Thanks

  • 3
    Don't operate the switch until it is dry. Many light switches will cause an electrical arc inside when the switch operates.
    – JPhi1618
    Mar 24, 2020 at 15:12
  • Use a 1:60 bleach mix for disinfecting let it sit for at least 1 minute or just leave it on. It is cheaper and safer. Mar 24, 2020 at 15:55
  • I'm voting to close this question as off-topic because it's about disinfectant practices. Mar 24, 2020 at 16:28
  • You might want to wait perhaps 24 hours, just to be sure, before operating the switch after the outside of the switch is dry if you do not want a surprise little pop! explosion. Or use something effective against bacteria and viruses like dilute washing-up liquid on a cloth. Mar 24, 2020 at 18:39

4 Answers 4


Water/ alcohol would be more of an electrocution or shock issue than a fire issue. Alcohol is flammable yes but depending on the concentration there’s probably more water, and water with impurities can make a conductor and shock you with contact being made on only 1 conductor , so I don’t see it as a possible fire hazard but as a possible shock hazard in reality. I spray any cleaner / sanitizer on a wipe then clean the device as the electronics are not sealed and it is possible to get enough moisture in the switch to get shocked.


It's a matter of quantity. The alcohol in such a solution doesn't evaporate "instantly"--it takes a few seconds and only when the solution is in mist form. If it collects in drops or puddles evaporation slows substantially. Obviously this would be long enough to bridge an electrical connection to detrimental effect.

30% of your solution is water, which is the primary concern. However, as you mentioned, you'd have to get enough of it past the wall plate and into the mechanism and maintain a closed current path. That would take a fair bit of liquid.

Unless you're spraying directly into the gap in the plate and a lot, it's not a concern.


The risk is electric shock. The alcohol, penetrating the switch mechanism, would become a current path potentially between you and the switch internals, which are hot.

A fresh pair of latex or nitrile or vinyl gloves should mitigate that risk. If in doubt, double layer with kitchen dishwashing gloves. We're dealing with 120V, not 8kv, I don't see call for hi-pot-tested gloves.


I believe what you are asking is if you mist the outside of the switch while doing regular cleaning, will this cause an electrical issue. And the answer is no, not with standard amounts of cleaner and practice. Just don't allow beads of solution to run into crack around the toggle and you'll be fine. You'd have to get what most could consider a lot solution in there for it to become an issue.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.