Yep, I've done that. Two Amex cards, one personal, one for my business. For a while, they even had the same last four digits, which was a total PITA 'cause there was an on-line vendor with whom I had both on file and they would offer me the choice of paying with the card that ends in 3005 or the other card that ends in 3005.
No it does not. My bookkeeper (who I also sleep with, but that's probably OK since we're married) catches that stuff every single time, as soon as the statements arrive.
Yeah... We have All made a Mistake. And that Isn't what get's an Ethics Committee or The Justice Department's nickers in a twist.
It's when they see a Repeated, Systemic and Brazen Misuses of Campaign Funds that they tend to move into action.
BTW - I want to know what the Name on the CC was?