My son’s bedroom is painted a dark green and a cheap paint was used. I painted it about 4-5 years ago. I have noticed the walls look as if someone wiped their oily, dirty hands all over it. The two outside walls seem worse but, it is around the whole room. Again it is not in one large area, looks like a really bad paint job and the walls feel sticky. I banged on the walls and they feel solid and strong like they should. There are no water stains and nothing else in his room has this. Someone said the paint has oxidized and this is the effect.