WASHINGTON — Credit unions can hold a campaign event in their offices but can't force employees to buy a ticket. They have to follow more stringent rules if persons outside the credit union are invited.

Those are among the federal rules to be aware of for presidential and congressional campaigns as the election season enters its final three and a half months. In state elections, each state has its own rules.

While campaigns bring out passionate opinions on both sides of the aisle, Congress and the Federal Election Commission have gone to great lengths to ensure that one person's enthusiasm doesn't interfere with the rights of others.