you'll often see a cat's ear twitch for no reason. that's because a ghost is talking to them. ghosts talk to cats constantly. they never shut up. that's why cats are so tired all the time. some random dead Victorian dude won't stop telling them how much mutton costs in 1872.
We think there's a ghost stuck in our LR wall. Ever since we moved in 7 years ago, one of our cats has spent hours per week staring fixedly at a point about 5 metres off the floor.