This proposed stunt is based on the Milgram experiment.
In the actual experiment, the learner received no voltage. Since we know how most people will react to this experiment, we can safely assume that our teacher subject will not shock our learner subject with enough voltage to cause any permanent damage. Our twist is that no one is in collusion with the producers. The voltage is real, but a safety switch will be installed, just in case.
I recommend that we choose our teacher subject based on his or her empathy score from the psychological profiles all contestants have taken. A teacher with a high empathy value is less likely to put our learner through much discomfort.
Our learner should be one of our "tough guy" types, in good physical health, who is more likely to withstand mild electroshocks better than most. For dramatic effect, it wouldn't hurt to play upon his fears. If he dislikes the dark, we'll have him in a dark area; if he doesn't care for enclosed spaces, we'll make sure he's in a confined area of the space I have in mind.
The location for this stunt will be...the room in the facility where electroshock treatments were given to actual patients! We'll be sure to dress the set accordingly, with bullets to bite on, patient restraints attached to the table, etc.
If the teacher administers the shocks above a marked voltage, where the safety switch is activated, he or she will be given a meal and a new piece of the map will be downloaded to his or her PDA. If the teacher refuses, the learner will receive the aforementioned items.