> I understand Australia/NZ have a different household electric current; not 110 volts as in the US...
That’s true. Both use 220 volts. And (believe it or not) the plugs are different!
Our telephone plugs are different, too. You use the RJ11c plugs, and we use something that is also four wire, but wider and narrower.
Getting a 220 volt shock is no joke! 110 volt is bad enough (had those back in Canada a couple times when I was careless). 220 volt is not pleasant at all — not even in jest!