Hello,
We live in a 1 1/2-level 70s house with a open staircase, like most 70s houses. We removed the lattice on one side of the upper floor a few weeks ago and put up another type of railing instead. Now we see that a nail is coming out along one of the moldings(?) which I guess belongs to the staircase. The lattice was not connected to any ceiling beams and was just from floor to ceiling, so I can't imagine it was load-bearing.
What could cause a nail to come out? Unfortunately poor pictures, but trying to show how the staircase is built and a picture of the black nail that is coming out.