It's hard to say what you should EXACTLY do since 'I cant see it from here'.
I can't say if it's OK to tap into the HOT wire. And as for the other one, who knows that that is unless you've traced ALL your home's wires. In short, if you can, run a brand new line to its OWN breaker. Or, hire a Pro to run the line and you can do the install. Be SURE you talk to someone who knows what's safe. (I know this is your question but again, I can't see it from here.)
My best to ya and hope this helps.
Jay J -Moderator