An extension ladder shouldn’t damage the wall unless you lose control of it or bang it. Wrapping the end with a cloth or buying rubber caps can help. When you move from side to side, try to lift the top away from the wall so you don’t scratch it; this is the most common way you could damage the wall.

They make stabilizers that often come with caps, but they will push you away from the wall; if you have short arms, this might be a concern. They also will require more space from the wall for the base to rest so you aren’t vertical.

Always try to have a buddy at the bottom of the ladder to make sure the base doesn’t slide out from under you, especially if you have anything other than carpet.