How did voting work in WW2?

Hi everyone,
I know that the US and UK held elections while the war was ongoing (in the UK’s case, only after defeating Germany). Ryan McBeth made a video discussing the legislation which allowed US soldiers to vote while out of state, and I know that British soldiers tended to vote for Labour (instead of Churchill’s Conservatives), but I’m also curious about the other aspects of voting in wartime. Which countries voted while fighting was ongoing? How were ballots transported to and from those serving? How did candidates and parties convey their message to voters at the front? What was turnout like?

Thanks for all your work!