light

[crsytat9988]

when u turn on the light where does it come from

[Sammy Snake]

When you flick the lightswitch it completes an electrical circuit and allows electric to the light. This heats up the filament inside the bulb which 'glows' and gives off light.

See here for a more scientific explanation!
http://home.howstuffworks.com/light-bulb.htm

[lankeela]

Sainsbury's - 2 in a pack for 49p.

[Marvin84]

another way to look at it is:
Do you turn on the light or turn off the dark?? ;-)