A perfect example of what I'm looking for is a position like this one, the "Blackburne Shilling Gambit"
1 e4 e5 2 Nf3 Nc6 3 Bc4 Nd4?
[fen "r1bqkbnr/pppp1ppp/8/4p3/2BnP3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]
The stats from Lichess show that Nxe5 is the second most popular move - being played half as often as the most popular move - despite giving a decisive advantage to black.
In this case at least, it's obvious enough that it's an intentional gambit from black and a dubious line to play into. In other positions, however, there's much less reason to suspect an otherwise typical opening move will lead to a tactic. I know I've certainly run into those positions when playing against an engine, though I can't remember any in particular