There are a lot of questions about this topic, but I'm feeling a little dense and want to make sure I do this correctly. I have a small office in my basement. Power runs from the breaker box to the switch, then from the switch to the light. The light is the only thing on the circuit right now. I want to add a new light and switch, where the new switch will be 10' away or so on another wall outside of the office. Everything is open except for the existing light, but I do have access to the existing switch.
Can I run a cable from my existing switch to the new one? What would the wiring diagram look like for that?