I know a few things about electronics, but transformers are still an unknown for me. I know AC to DC converters use them to isolate live voltage from the DC output, or at least I think that's what they're used for.
Dumbed down, the transformer is just a bunch of wire coiled over a core, that's usually made of steel (at least for larger transformers) which is very much conductive. Couldn't it ever malfunction in such a way (wire melts or something) that the 2 sides of the transformer become connected and the output becomes live?
Say I have a 240VAC to 24VAC transformer. Is there any chance the output can reach 240V if the transformer overheats or breaks down in any way?