I once was asked to look at someone's kitchen outlet for the microwave, it kept having problems cooking.

I unscrewed the cover plate for a look-see before bothering to turn off the power and ZAP...darkness as the breaker tripped. Getting a flashlight, the outlet wasn't in a box. Just a hole in the wall with outlet hanging off the cover plate. Ok, that explained the larger plate than a normal USA one.

Fished the outlet out of the wall and on the back was the crumbling remains of brown zip-cord going straight into the wall and to a box on the other side. Opened THAT box and the two wire cord was just tucked under the screws that held the original building wires in.

I added a box, real 3 conductor building wire and put the wall back together. MUCH better.

Some wiring jobs are scary, others are worse.