We are the meat in the Sandwich

Which brings us to the setting for this little drama: our apartment. We are the meat in the sandwich. That is, we live on the second floor of a three story building. It is an entirely wood-frame building. Stomps, slams, wall bangs, even taps, especially those from above, are quite noticable. The apartments above and below are mirror images of one another. There are twenty three apartments and one laundry room.

The apartment stacks share a common inner wall interface. That is to say that if you were to blow air into the inner wall of the apartment above, that air would find its way down into the two apartments below by way of that common inner wall, through various holes created in the structure for plumbing and wiring. The air would escape through various wall openings such as electrical outlets.

(0830 and the numbers are now 3.7 million bytes and 42.4 bytes.)

Knowing these structural facts you could, if you had a nasty disposition, a vaccuum cleaner, and some sort of noxious gas like pepper spray or mace, make life miserable for the folks in the two apartments below: You could devise an 'attachment' to your vaccuum cleaner blower such that you could inject that gas into the inner wall under pressure through (for example) your own electrical outlets. The gas would then seep into the apartments below. There is a problem with this if you only want to gas the folks in the middle apartment: you would have to seal up those openings in the walls of the bottom apartment. Or, you could simply rent the bottom apartment and not occupy it. Or both.
(This would be expensive only if money was a problem, which it isn't in this case.)

That is what is actually going on here. In addition to being harrassed from above by stomps and wall bangs, etc, I am being gassed.