Customer lost most of the power on the second floor. Customer had covered the rafters in the attic with 3/4" particle board. Circa 1920's house.
House had been wired in stages - knob & tube, later grey fabric romex (no ground), still later white romex with small ground. Tracer went crazy trying to trace which 4x8 sheet to lift up - finally found this jbox (5 others found - buried under pink stuff and cellulose) - under 7th sheet - fortunately they were all screwed down!
I was taught to twist wires together, making them mechanically sound, and regard the wire nut as a secured insulator - it appeared that these wires were just stuffed in and twisted.......
An excellent picture. Looks as if there was plenty of heating that could have very well resulted in a fire. The metal box did well in containing any arcing and heat. But knowing that it wasn't grounded there was no way that a breaker would have been tripped unless there was a massive line to line fault.