On my Nokia lumia 625 the camera flash is stuck. When I go on my camera though, it switches off, but when I go back on my home screen it goes back on!! Someone please help!!!!!
You could have it toggled on somewhere. I'm not sure where.
Safest bet is just to do a restart on the phone. To do a soft reset, simply hold down the power button and the volume down button at the same time. Hold them down for about 10-15 seconds, or until the phone vibrates and restarts itself. That should do the trick.