Just for the heck of it, I did a search to see if I could find any more info on this glitch, and I did come across something similar you can do in the residential area. Quoted from here:
"Go towards where your friend with the yellow jacket lives and go up the stairs. Wait in the middle of the flight of stairs until someone is coming down and someone is going up the stairs. You will become stuck. Keep moving around, and you should walk out on to the air. Note: This works best at night. You cannot use it to get to hidden areas and is difficult to do."
Has anyone ever tried this before? It isn't very specific, unfortunately. Who is the friend with the yellow jacket? Mrs. Kondo? I went over to her place, but there is no flight of stairs anywhere nearby. Is there someone else I'm not thinking of?
I also wasn't sure what it meant by waiting in the middle of the stairs, since you don't have that ability in this game. Unless the stairs in question are actually split in two, with a little flat area in between.
I guess it would also help to know the schedules of the residents in the area, so that maybe you could pinpoint the exact moment when you need to be on the stairs, just as someone is trying to go up and someone else is trying to go down. Can anyone shed any light on this whole thing?