I have seen the result of two mobile chargers blow up in the office - the fire was only prevented by fuses and even so there were black scorch marks on the power outlets. My dads battery charger blew up similarly.
In all cases it was because they were brought cheap on Aliexpres. I haven't seen any chargers sold elsewhere have any issues. The closest thing I got was when I charged my laptop on my bed and had put the blanket over the charger - it didn't fail but it got really, really, really hot.
So based on anecdata: don't buy things things to stick in walls on aliexpress. Also fuses are really nice.
A lot of the chargers and cables you find in gas stations and the like are identical to the AliExpress junk, so it’s a good idea to be wary of those too.
In all cases it was because they were brought cheap on Aliexpres. I haven't seen any chargers sold elsewhere have any issues. The closest thing I got was when I charged my laptop on my bed and had put the blanket over the charger - it didn't fail but it got really, really, really hot.
So based on anecdata: don't buy things things to stick in walls on aliexpress. Also fuses are really nice.