I vaguely remember a post on GAW a few months ago of something quite similar to what Trump did with hush money and campaign funds, I've only found these articles so far.
https://www.politico.com/news/2020/07/31/sanford-bishop-allegedly-misused-campaign-funds-389742
Congress actually has a fund that they use to pay off those accusing them of various wrongdoings, usually sexual in nature. This is how they keep it hidden from We The People.
And I think I read that the records of who used the funds is top secret.