§ 2507 Political vote.

Here's a plain English summary of this rule.

If you voted in a political election using a secret ballot, you have the right to keep how you voted private. Nobody can force you to tell a court which way you voted. This protects your privacy at the voting booth, even if you end up as a witness in a court case.

There's one exception to this rule. If a court finds proof that the vote was cast illegally, you lose this protection. In that situation, you can be required to reveal how you voted.