In a nutshell the ghost hunting parts were shot semi-straightforward. Just give the guys some cameras and watch them react to being in dark spaces with overly active imaginations. Then those scenes are edited for maximum dramatic impact with lots of over the top enhancements like music and sound to make certain scenes effective. But most of the techniques like the meters and sound recordings work like Ouija Boards... People see and hear what they imagine could be a ghost because that's what they're trying to see/hear. It's almost like cold reading.

But none of those shows would work without all the post sound additions that create 'scares' and big moments. Those sounds make most of the scenes feel much more intense than the raw footage ever shows. The audience doesn't know which parts those are so it feels bigger than it really is. Having to sit through the raw footage makes it pretty compelling to me that ghosts really don't exist to anyone unless you reaaaaaaaallly want to believe.

However the non-ghost scenes, like work and family stuff are pretty much directed and slated and shot with multiple takes like any dramatic narrative fictional TV. You give the performers their motivation and then they improv reactions and dialog. That format is how most of reality TV is done. Actors and comedians are even hired to play 'old friends' and 'family members' of characters.

There are also story producers brought in to create narratives through editing and reaction shots are intercut with different scenes to make it appear that reaction, emotion, and tension is much more amplified than the raw dull footage actually shows.

There are very few 'real' reality shows on television. I think the handful I can name are Intervention, COPS, First 48, and a few others. Most are just light cheap dramas and soap operas dressed up in documentary video style garb.

In truth the behind the scenes of most reality shows is MUCH more intense and drama-filled than what goes on in front of the cameras. It's an ugly business