It’s usually just funny but occasionally can be deadly: a cat goes to sleep in a clothes dryer, and someone turns the dryer on and walks away. This is most likely to happen when there are several loads of clothes being done: the dryer is already warm from a previous load, and the cat sees the door open and decides the dryer would be a warm and cozy place for a nap.
In comes the next load, on goes the dryer and the cat is taken for a spin. In most cases, the owner will quickly get an earful of noise to let him know the cat is in the dryer. Usually no harm is done (after all, the cat is surrounded by clothing), but in some cases cats have died from suffocation.