How to deal with paint peel on normal wall
You need to figure out why the paint is peeling, address the problem, and then re-paint.

In many houses, the chances are that the paint was not properly applied - the wall was dirty or damp.

The first step is to remove the peeling paint.  If you're lucky, it's just one wall or a small patch - otherwise, you'll have to do the entire wall or room.  Start by scraping off as much loose material as possible, and then sand around the scraped areas.  Make sure that there aren't any places where the paint hasn't adhered, but hasn't started to flake yet.

Next, apply a coat of primer/sealer.  You may find at this point that the first coat loosens the existing paint - you'll need to decide whether to go back and remove more depending on how bad it is.

Finally, after the primer has dried, repaint.