Fix wooden wall paint
Hard to tell from the photo but it could be latex paint over wallpaper. The fix is easy. 

Using 80 or 100 grit sandpaper, gently sand the edges of existing paint and exposed surface. Remove dust and debris with mild solution of trisodium phosphate dissolved in warm water. Let dry. 

Apply thin skimcoat of joint compound or sparkle , feathering the edges to existing paint. After dry, lightly sand. 

To match existing wall texture (which looks like medium orange peel), using a small, disposable paint roller and thinned joint compound, apply texture. Let dry, light sand. Remove sanding dust and paint.