This looks like a male yellow sac spider. Have you observed any daytime sleeping sacs (usually in the corners of your ceiling)?
I agree with JoRo20, definitely a sac spider. Poor little guy looks pretty emaciated.
The males focus on getting to the hot female spiders, not hunting. Lots of walking and not much eating is a successful diet plan for him. That just triggered something I was trying to remember…..that there are moth species where the males are born without mouths. They hatch, mate, and die. I don’t know if that is sad, or Livin’ the Dream.
Good to know! I’ve seen a couple pretty thin little guys on my wall and I always give them a couple fruit flies. Maybe that’s why I have so many sac spiders 😛