When I moved in, the first purchase was battery powered smoke detectors, as the house had none. Lived in another rental place where the owner decided to save money on junction boxes - all the splices were flying splices in the ceiling. Woke up to a glowing ceiling one day (no idea how I woke up, but thankfully I did) - after that scare, won't live anywhere without smoke alarms.
As for the SE cable, they tried - they put white tape on one of the blacks...
