I got a maintenance contract with a property management company in 2013. They own numerous section 8 apartment buildings around town with a total of 131 apartments that are all nearly identical in layout and building materials used. The electrical systems and wiring are about 35 years old. The strange part is that it's as if someone threw a switch and all the apartments' wiring is failing at the same time and in the exact same way. These photos are from different apartments and buildings and they all have burned out wiring. All the devices are back stabbed and the splices are crimped and wrapped with tape. Has anyone seen this type of situation before?