You need a hole just large enough in the wall to drill a hole through the top plate I think it's 1-1/4 from the edge. I use a flexible extension for my spade bits and it works great. Then I work my fish tape through the wall into the ceiling using the hole you used to drill through you will need to use a coat hanger or fingers to line the fish tape up with your hole. Then you may also need another hole in the ceiling near the wall to hook onto your fish tape to get the fish tape going the direction you want.
If the wall in insulated you can use a thin piece of wood or something to push it out of your way so you can drill. A helper comes in handy.
When we gutted our bath, I took a crowbar, pried the corner far enough that my son could get his fingers back there to push through the other side. It took some trust. Even with a coat hanger, it is hard to do.
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!