This article starts off one way (warning conservatives about scam PACs), but reading into it, I found something I never knew before.
Apparently to become a PAC, you just have to register, and then give *some* money to a candidate, doesn't matter how much, or what percent.
Scam PACs are a thing, they take donations and then put 99.99% of those donations into "operating costs" or "administration salaries"
https://workplacetablet.com/2018/10/29/conservatives-targeted-for-midterm-election-scams/