I noticed that an electrical outlet on the outside wall of my house is well sealed to the siding with caulk, but the outlet (with vinyl siding) float and can be push/pulled 1/2" each way. I was prepared to put the retaining strips in the hole beside the outlet box and bend over the tabs to prevent the box from being pulled out. After removing the outlet, I saw that the metal box is screwed to the siding, and nothing else. I removed the box, and found that the particle board sheathing has been bashed in rather than cut. The crater is about 6" in diameter. There was a vacated wasp nest in there, and the insulation is compressed against the drywall also. I am guessing the builder forgot to install this outlet and retrofitted it with a hammer. All the other outside outlets feel secure, so for now I assume they were installed correctly. I want to repair this, and get the outlet secured to something solid. I also want to get a better vapor and insulation seal at this site. It is a great source of air infiltration. I assume I should open the wall from the inside and put a piece of plywood over the sheathing hole larger than the hole and fill in the missing particle board with a custom piece. Then I will cut a rectangle for the outlet box and screw the box to this reinforced sheathing. Is this necessary or advisable? I think I can do this without removing any siding, because I am concerned about cracking it if I remove any. It will probably need a 10x10" wallboard hole, I think, and that is not very appealing, either. Is this what I should do?