What happens in France if I personally fund a bunch of billboards to advertise for a politician? While, the campaigns do receive tons of a money there's also a

What happens in France if I personally fund a bunch of billboards to advertise for a politician? While, the campaigns do receive tons of a money there's also a lot of non-campaign expenditure in the way of things called PACs/Super-PACs which basically produce the same ads that you could see from a candidate minus the "and I'm X and I approve this message.".