Exposed Wall Wire Mesh
The exposed wall wire mesh in this wall was caused from
water damage. A pipe was leaking for a while, until it actually loosened
up the plaster and the homeowner could only clean up the mess that was
made on a daily basis.
As a contractor, I see plenty of home repairs, that can't be fixed when they should have been, simply because the homeowner lacks the funds required to pay a contractor or handyman to repair the damage.
Sometimes when I get to a house, what could have been a small water pipe repair, will now require wood to be replaced, flooring to be removed and replaced, walls and ceilings to be repaired and the small water pipe repair, will usually still need to be made.
Anyway, this should give you a pretty good idea, how they use to apply metal wire mesh, over a thin layer of drywall.
Here's another view of the damaged wall. Rarely do you see a 1 x 4 piece of wood trim, installed as low as this one was. I don't really know what the purpose of it was. It could have been strictly cosmetic.