Serious question, do you fish the wall before you mount the box or after?
Had a rough one yesterday at a two story in Clearwater where I had to drop a line down an insulated exterior wall for a new outlet. I could either cut the drywall first and see what was in there, or fish blind and hope I missed the fire block and the romex already running down the stud bay. I cut first and found a nest of old knob and tube plus a diagonal brace right where I wanted to drill, so I moved the box over 14 inches and it went smooth. My partner swears he never opens up a wall until he has already fished it and he hardly ever has a problem. I feel like I waste 10 minutes patching but I save myself from drilling into somebody's wiring. What do you all do on a finished wall, cut and look, or send the rod and pray?