The Trigger Happy is for "Disarming 50 door traps"
This is specifically for the electric spike door trap. If you crouch to approach them and open the door they won't go off. Then interact with the battery pack on the wall next to it to disarm it.
Each trial has a few of these and you can't really farm them. So just be careful with doors to try and maximise the number you can clear.
Also two handy things to note:
1. The in-game badge menu tracks your progress.
2. Leaving a trial after gaining progress still counts towards it.
Video guide for reference: