Error 220, which was named Error 219 before it, is the name of a computer virus in the Regular Show episode "Skips vs. Technology".
Techmo: This is the worst error 220 I've ever seen. I've got no choice - I'm jacking in.
Skips: Are you sure we just can't smash it?
Mordecai: Skips! Just let him do his thing!
The error that occurs (at least in Europe) when you connect the expansion bus on a computer directly to the power line. May result in some light phenomenons. US readers may be more familiar with the similar Error 110.