The project in the hall was one that we knew needed to be done, but weren't sure when. However, the replacement of the front door with the removal of the door trim helped us decide. Also, the fact that the front porch light mysteriously stopped working and we needed to dig into the wall to figure out the wiring for that helped us decide as well.
This project led to several others in the process. We had to dig into the front wall in our bedroom (I will post that later) as well as run wire for a new porch light, a matching light on the opposite side of the porch, and a porch ceiling light which was missing. While we had things torn up, we decided we probably should put in an electrical outlet at the base of the stairs, so that led to tearing out the hall wall under the stairs. (*whew!*)
We're still not done. The trim needs to be redone for the door (it is a bit taller than the old one) and the switch plate needs some shim work because the outlet box is sort of at a weird angle. We also need to do some touch up with the paint. But now, the walls are no longer sagging because the plaster was pulling away from the lath.