Basement stairwell walls

Last night I sanded down the walls to figure out where the high spots were, and slapped some more spackle on the divots and holes.

Left side - Fixing up pretty nicely, actually.
One more sand and this one should be good enough to prime.

Right side - this side is a bigger pain in the next because the rail is in the way, and there was more damage.
The patch above and around the light switch is slowly getting better.
This side will need another round of spackle and sanding before priming.

Stay out!

That last picture is from where the wall of the right side of the stairwell joins the stairs above. It's the most amusing, ridiculous thing. The hole is maybe 7-8" long, and maybe 3" high, and blocked with 4 large framing nails (?).
I'm not entirely sure what we're keeping out (or in). Mice would dance right through the gaps. Rats? (Have seen no evidence of rats.) Squirrels? Cats? Wombats? A rogue wallaby?
I don't know, but I'm leaving it alone as a point of interest.

Not much of a visual difference, but I'm puttering away on it.

When I'm allowed too, anyway.
Good thing it's hot, she's not all over me for my lap right now.