I want to hook up a light to an exsiting light switch?

Question:i know electrical i would just like someone to tell me about it or somewhere where i can read about it. the switch is already hook up to a light.

Answers:
If you want the switch to operate both lights, you can run new wire from either the switch or the existing light.

If you want just the new light, unhook the wires for existing light and run new wire from the switch.