when coming down a stairway
In the dark you may not see the cat sleeping on the step, and to avoid squashing said cat, one twists, turns and falls; causing damage to the wall
Upon hearing thumps and a boom, I ran out of an upstairs room into a dark hallway, flipped the switch to find ol Frank picking himself up off the stair landing. After ascertaining he was not hurt, proceeded to lecture him on the value of light in a stairwell.
Especially when said cat is 15 years old and has slept on that step most of the nights of his life.