Well, this morning the ground fault breaker switch had dis-engaged itself again. Which is odd — we thought we had fixed it by completely removing that wiring tube from the system altogether.
We do have a large extension cord running up the side of the refridgerator, and last night I caught the cat sitting on the fridge — he had jumped onto the kitchen sink, onto the oven and then onwards to the fridge.
Maybe he has been toying with the wires, but I see no obvious signs of that.

It gets curiouser and curiouser.