Here is the official JW position from the "Keep Yourselves in God's Love" book, page 213:
What should a Christian do in lands where voting is compulsory or in a situation where feelings run high against those who do not go to the voting booth? Remembering that Shadrach, Meshach, and Abednego went as far as the plain of Dura, a Christian, under similar circumstances, may decide to go to the booth if his conscience permits. However, he will take care not to violate his neutrality.
The basic message (which they are too cowardly to put into print for fear of lawsuits / fines / taxation) is, "go to the voting booth, yes into the literal physical booth itself, but don't actually vote for anyone".
I think I've heard anecdotes about JWs producing write-in votes for "Jehovah", "Jesus Christ", etc.