SUBREDDIT: r/tifu
TITLE: TIFU by plugging a laptop charger into a portable vacuum.
POST: The roommate and I decided it was a good idea to charge our vacuum (one of those tiny handheld ones) with a laptop charger that conveniently fit inside of the charging port! Everything was normal for about an hour, and then we started to smell this foul, burning plastic smell. We didn't think that the vacuum was the issue, assuming a nearby exposed heating pipe was the source of the stench. Long story short, that shit started smoking and burning. it was unbearably foul smelling, and it still is, hours later. Judging by the black smoke, it was probably minutes away from complete combustion. It has been airing out by a window for a couple hours and it still smells like plastic-y, burnt, hell.
TL;DR: 
used a powerful laptop charger on a shitty vacuum and made black smoke and a terrible plastic smell fill and linger in my room, almost reaching combustion.