I applied online. I interviewed at Yale University (New Haven, CT) in Mar 2017
Interview
You had to prepare a section of the campus tour to perform in front of a interviewer, who is a current tour guide. It was really laid back, and they didn't mind if you made an error or two, however NEVER make something up if you don't know it.
I applied online. The process took 4 weeks. I interviewed at Yale University (New Haven, CT) in Feb 2015
Interview
There are three rounds: First, you do a written application and a panel interview in front of a few current tour guides where you give a short spiel. Second, you do two interviews with current tour guides. Finally, you give an audition tour to a real group of guests based on observing other tours.