A friend of my wife called yesterday because a rechargable battery she was charging had burst into flames and she had to put it out with plant soil. Good thing she didn't leave it to charge overnight...
I was asked to help figure this out. So I started asking about the charger and the batteries. It turned out the rechargable battery (presumably an AA cell) arrived earlier the same day from... #AliExpress
Don't get batteries and phone chargers from unknown sources. These can burn your house down.