It is driving me crazy. I don't know what it is, but I need to know what to do. It happens mostly when I am awake during the morning and daytime. I bang on the wall and it stops for like 15 minutes, but that is it? What should I do?
Figure out exactly where you are hearing it, then you will have to find an animal trapper to come get it out...then have your wall fixed. In my late teens there was something in the wall of my bedroom, I envision it being a squirrel; I told my parents about it waking me up with the scratching, but since it wasn't in their room they didn't listen.
I am pretty sure that if anyone ever takes out a certain area of that wall, they will find a mummified critter in there. The sound just got weaker and weaker til it stopped. I don't recommend that approach, because if the conditions aren't right for it to mummify you will end up with one heck of a smell on your hands...for a long time.
Mice? Roaches? You should call several exterminators and ask them for a telephone assessment, as I'm sure they will have experience with your "symptoms". I'm glad you are not ignoring this. You live in a house, right? Good luck.
We had the same problem with noises in the wall. Thought it was mice, but turned out to be bats. Noticed them flying out early one morning.