Alctel:
I was on my H36 today and did take a quick look-see in regards to your post.
I really don't think it is possible to view the wires that are routed between the interior lining and the bottom side of deck/cabin top. My first blush is that you should at least remove each of the AC outlets. (I didn't count, but from memory there are three on each of the starboard and port sides. Note their condition. Unscrew the terminal screws on each outlet and observe the wire condition. These locations are where time and moisture will have done its damage. Not so much along the rest of the wire that is protected by the insulation. If the wire ends are corroded or tarnished black then certainly replace all the wire with marine grade tinned type. And the DC wire to the salon lights is also likely suspect. In my case, when I inspected, each receptacle still had shiny metal and the exposed wire that was wrapped around the screw terminals looked still looked metalic. But also, my PO's didn't drill any holes in deck that leaked water!
I think that I mentioned before that you should consider replacing the first receptacle on each of the port and starboard circuits with a GFIC type unit.
regards,
rardi