The GA standard is a 1/4" plug for the speakers, and a 0.206" plug for the microphone. The latter stems from the telephone switchboards of the early 20th century,
Actually, they both stem from that source, Ron. The Bell System was still using both at least into the 1970s. And not just the plug/jack, but also the electrical characteristics (impedance, etc.) were also telephone standards, to the point that I was actually able to take an early electronic telephone headset and easily adapt it to aircraft usage, mostly by changing the plugs.

I think phone chargers and electric razors have different plugs and voltages there, but again Im not sure.
Many countries use 240 VAC where the U.S. used 120 VAC, and many countries run that AC power at 50 Hz (cycles per second) vs. 60 Hz in the U.S., so yes, those items are different, but they have nothing to do with what aircraft use.

So if your helmet has the ¼" audio plug, and the .206 mic plug, it should work fine in their aircraft that are so equipped. But if your helmet has the military style 4-conductor plug (I think it's similar to many helicopters here) then it'll only work in aircraft so equipped.