I have an exterior, wall-mounted light fixture that I want to attach to my new garage. It looks like this:
Here's a PVC board the contractor left to mount it. There appears to be OSB sheathing board behind the PVC, then the house-wrap, then the OSB sheathing that's nailed to the garage studs. The whole thing is about 2 inches deep. There is no hollow in it. I know this because I drilled a hole through the center of it. You can see the hole in the picture.
This is what it looks like on the inside of the garage. In the center of the photo, you can see the same hole.
My light needs a junction box behind it to connect the wires to NM cable inside the garage. Since the mounting block is solid, I can imagine routing (not cutting) an octagon into it to insert a very shallow junction box, or I can imagine cutting an octagon all the way through the wall to insert a deeper junction box.
What I want to do instead is just to mount a junction box inside the garage, and pull the wires from the fixture through the hole in the wall. My connections would all be inside the garage and I'd avoid a big hole.
Is this allowed? If there is a problem with pulling those little unshielded wires through an exterior wall, could I get around it by inserting a 2" length of PVC or metal conduit through the wall?