They could start dating a "bad boy" who likes to hit holes in walls.

Perhaps the basement or exterior wall was not sealed correctly after the electric, gas or water was split to be metered per unit. 

<coldblooded>I feel sorry for the person who tried to off himself but with my anxiety and paranoia there is no way I could live peacefully with them one wall away from where I lay my head. 

Trying to convince people that permitted work is better is like beating your head against a wall.

Technically you will not "share" a wall in spite of how it looks, technically there are typically two complete walls... they just touch and good luck separating them after 15 years.

I don't want to keep the existing one but am afraid if I tear it off it might damage the existing wall.  

A regular shower rod is either secured by compression and screwed in, I assume the curved rod needs to be secured to the framing behind the wall? 

Today, I am hearing things in the attic and occasionally in the walls - maybe rodents? 

I know its possible, but am just hitting the proverbial wall.

If you have lights that hang from the walls (not ceilings) and baseboard located plugs, it may (no guarantee) be an indicator that there is knob and tube.