For the last couple of nights I’ve been hearing a popping/thumping sound occasionally outside the bedroom window. It happened only occasionally and I put it down to something swinging in the wind and hitting a wall or the neighbours next door slamming a door. But yesterday there was no wind and it was happening in the morning when I knew the neighbours were out. I investigated. Of course, when I went outside to look, it didn’t happen.
So I looked for loose items. I checked the hot water system gas burner. While I was doing that, I heard the sound again, coming from a few yards away near the side of the house. When I went there I could swear I smelled a burnt odour.
With a torch, I looked under the house at the electrical wiring. One piece of cable was dangling a little between supports. I looked closely and it looked damaged. I flexed it. There was pop and a spark. Sure enough there was what looked like a burn hole in the cable.
I turned off all the power, pulled all the fuses, grabbed my insulated gloves and tools, checked that the wires were no longer live and cut away the damaged section of wire and rejoined it with cable slicing gear I had in the shed.
Here’s what the burn hole and the damaged inner conductors looked like. The Active wire was arcing to the Ground, which was completely burnt through. The Neutral line was OK.

Once fixed, I began to wonder how close I was to a house fire, so I tried burning a bit of the insulation using a propane lighter. It wouldn’t maintain a burn at all without flame continuously applied, so my guess is that there wasn’t much chance of the house going up.