This junction box is designed for just 4 cables.
Here you can see someone has managed to cram in 13!
This is a potential fire hazard when hidden under the floorboards.
Unfortunately there is a considerable amount of DIY electrical work not being carried out in accordance with regulations and safety.
The wiring shown was found in a loft extension, the owner of which was a DIY fanatic.
Inappropriate connectors, overloaded junction boxes....
Another potential fire hazard!