> On the other hand I read a long time ago 120 V causes way more home fires because of higher currents.
[citation needed]
All domestic mains plugs found in typical residential circuits all over the planet are ≤20A:
* https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Com...
The vast majority of 120V plugs are 15A; if you want 20A it's actually a special case:
* https://en.wikipedia.org/wiki/NEMA_connector#Nomenclature
So there are no "higher currents" used. If you need more power then a higher-voltage NEMA 6 plug, or a two-phase NEMA 14, socket is typically used.
For a 1kw appliance, with 220v it should be 48 ohms, but for 110v it needs to be only 12 ohms. So if you have a bad wire or connector, which has say 5ohms resistance, more of the voltage will drop across it. At 220v it will have 21v across it and be heated by 88W but at 110 it will actually have 32v across it and be heated at 204W. That could easily be the difference between a fire starting and not.
Americans have to worry about chaining power strips, or overloading them with the Christmas lights.
That's much less of a concern in 230V countries.