We are just finishing up (cross our fingers) our first Wisconsin winter in our new (to us) home and the other day notice something strange along the exterior walls. Roughly 4 ft up from the floor a horizontal line is visible that continues down the exterior wall. If you run your hand down the wall (From top to bottom), you can feel a slight bulge right where the line is. It seems to be at the seam of the drywall.
The house is roughly 40 years old. There are no cracks in the anywhere on the drywall, which leads me to rule out a foundation issue. Could this be bad mud/taping/hanging job the builder? or cold weather related? or something else?