Selling fraudulent goods & services is a violation of copyright or contract law, not free speech laws. Putting a UL logo on a product not tested by UL means you are violating their copyright. And you can claim your product does almost anything, but if someone buys it and it doesn’t, and it can be shown that you deliberately misled them, then you can get in trouble.
Both of these examples are nowhere close to the power given to the government before Citizens United: a censor who chooses what people are allowed to read or hear in the months before elections. Unlike copyright or contract law, the punishment was before the fact, not after. And it applied to films people paid to see, not just ads.