I have a 3 year old tabby that for the last few weeks has started jumping at the light switch on the wall during the night. One night, she even managed to turn the light on! I have also caught her standing on the top of my sofa, and jumping up as high as she can against the wall as if there was a bug - but there isn't anything there. I have noticed that if I leave a light on, she will lay down and go to sleep. But if it is dark, she will wake me about every 1/2 to 1 hour all night jumping against the wall at the switch, or at other unseen things on the wall. Can cats become afraid of the dark? No other unusual behavior. She is an indoor only, spayed cat. Any thoughts?