Not sure. Most time I read in the newspaper when some apartment burnt down, or this happens somewhere in my vicinity, it is something that was plugged in. It’s super rare that this happens with unplugged chargers. So I’m pretty sure there is some chance this happens, but it’s more complicated than that. For example during sleep, the human nose seems to be on standby as well, so you might not notice if your e-bike battery or your hoverboard which you’re charging during the night will catch on fire. Until it might be too late. You won’t be noticing the unplugged charger either, but it’s less likely to fail catastrophically. But you should be worried about both. Especially the hoverboard. And not being present has the downside the fire is going to spread. But as an upside you can’t die from the fire if you’re not there. But yeah, if you’re sitting next to it and act quickly, you can stop a situation from escalating.
And firemen always tell, people are surprised how quickly a fire turns from small to all the furniture and plastics stuff burns and it’s not something a regular person can extinguish or contain any longer. So you really have to be right here. One room apart might not be enough.
I agree. We already moved the goalposts a few comment further up the thread… (And I meant plugged-in chargers that have nothing attached with my bad phrasing with “unplugged”) I just wanted to tell that some of the ways to mitigate for the risk aren’t very straightforward. What seems to do a lot is get smoke detectors, and a fire extingusher, so you don’t spend the deciding 2 minutes in the bathroom, filling up a bucket. And some risk is always there, we almost all own quite an amount of electronic devices and batteries. (And then what people said here, don’t use dubious products with less failsafes in their design, and entirely unplugged things (without a battery) are safe and will not cause a fire.)