Votes aren’t counted until January.
On the other hand, you’re right - sort of.
In 1960, an elector pledged to vote for Nixon offered to vote for Harry Byrd if Democrat electors would join him.
So far as I know, it’s just honor system - the faithless electors would not know for certain that the bargain was kept.
Until the votes are counted that is....
Technically true, but the news media cover the the electoral vote. If someone votes contrary to how he or she has been pledged, the media Will report it especially if that vote could result in a cacandidate that was not on any popular ballot being made a candidate for consideration by the House.