SAFETY SYSTEM SAVES HOUSE BURNING DOWN!

This is the worst case of an overloaded, shorted electrical receptacle I've seen. Too many wires connected to the device, overloading  by using a portable heater led to this near disaster.

In this case the breaker tripped as it was designed yet the damage to the device shows heat was a major factor for a long time until the wire's insulation burned away and caused a short which, thankfully, tripped the breaker.

In addition to the side terminals, the push terminal in the back of the receptacle was used which is unsafe. Pigtail was used to tidy up the wires and terminate with just screw terminals.

If your lighting/electrical system flickers, this is a sign something like this might be happening. A tripped breaker is the first sign your system is in trouble.