I am about to insulate my exterior walls and it was recommended that I run any wires I may want in my attic now...before it is too late. I already have two light fixtures, an attic fan, the electrical to the bathroom below, and box with two switches (I never use the right terms...fuse, breaker, whatever). All I know is when I rewired an outlet incorrectly, I had to go up there and reset the switch. Do I need more wires/power if I plan to finish out the attic for a possible office or guest room?