You could always say that you were doing this:
The November 15, 1950, issue of TheWatchtower, on pages 445 and 446, said: "Where Caesar makes it compulsory for citizens to vote . . . [Witnesses] can go to the polls and enter the voting booths. It is here that they are called upon to mark the ballot or write in what they stand for. The voters do what they will with their ballots. So here in the presence of God is where his witnesses must act in harmony with his commandments and in accordance with their faith. It is not our responsibility to instruct them what to do with the ballot."
WT Nov 1st 99
They mean that a dub has to spoil the voting paper or write " I vote for Jehovah's kingdom" on it ..If voting for a candidate is admitted , you are OUT as a d/a as soon as wink...