It might have happened that when you are in a public or work toilet the light turns off because of the motion sensor, and as much as you wave your hands you cannot make it on again.

Is there an easy way to turn it back on again?

  • Can you confirm whether you are in a stall when this happens?
    – holroy
    Commented Dec 8, 2015 at 23:05
  • 1
    @holroy I can confirm, but I won't...
    – cinico
    Commented Feb 1, 2016 at 18:32

7 Answers 7


I'll assume the light won't turn on again because the sensor can't spot your hands moving within the stall. The door and the stall walls block the sensor's "view". I can think of a few options:

  1. Try leaning back and waving your hands overhead, almost brushing the wall with your knuckles, and also moving your hands far to the left and right. That might allow them to be "seen" over the door.
  2. Slide your feet forward under the door, then move them left and right. This might allow them to be seen "under" the door.
  3. If you can reach the door, and it opens inward, open it and close it again.
  4. If you have a jacket with you, hold onto one part of it and carefully throw the rest of it up towards the ceiling, making sure to quickly "reel it in" so it doesn't touch the floor.

If the lights gone off - there's no one outside the stall.

So open the door, wave your arm about and be enlightened.

  • 8
    And then somebody walks in exactly at that moment and then you are both enlightened. Commented Dec 16, 2015 at 5:08

I recently found out that many toilet motion sensors are based on a radar principle, and they use microwave radiation for that purpose.

Thus, a very easy way to trick the motion sensor is to pick your mobile phone and start making a call. You don't have actually to make a call, just let it start making the connection as the microwave radiation will immediately interfere with the motion sensor and turn the lights back on.

  • 1
    I think you are referring to Tomographic motion detection, but I don't think it is related to the signals of the using the cell phone. I'd love to see a reference to what you are referring to and whether this is actually used on public restroom-style situation. Thanks. Commented Dec 8, 2015 at 15:58
  • @RobertCartaino I am not referring to tomographic motion detection. I am talking about Microwave Motion Detector which is commonly used in toilets. homesecuritysystems.tips/types-of-systems/…
    – cinico
    Commented Dec 8, 2015 at 16:13
  • 3
    Worst-case scenario: now you're in the dark sitting on a toilet which is automatically flushing due to its motion sensor. Also your mom somehow noticed your call which wasn't supposed to actually connect and calls you back, causing another flush. Commented Dec 8, 2015 at 20:33

The sensors used have a range of x meters. One have to be in that range to interrupt the sensor which will in turn trigger the light/s.

Best approach - look out for sensor and judge the range. If you are in the range zone, it should trigger the lights.

Thank you.


If the motion detector is actually next to your cubicle, then you are in luck - otherwise you might have to cross a few doors to get it light up again (happened to me, not funny).

  1. You can always throw out something, over/under the door, just be mindful not to throw anything you might need before you leave your post.
  2. Use the torch function on your mobile to cast some light outside of your cubicle - that might trick the sensor to think there is movement.

I had the same problem in school and found out that on some motion sensors there is a little switch to set the light to always on. So it was in my school, I don't know if it is in your toilet. Don't forget to switch it back to motion detection when you are finished. :)


Something very simple that wasn't suggested here yet: close the toilet seat, and stand on it.

This might trigger the sensor.

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