Yes, there is a superstition about clocks falling off walls. In some cultures, it is believed that if a clock falls off a wall, it is a sign of bad luck or even death. This superstition may have originated from the idea that clocks are connected to time, and that if a clock falls, it represents a disruption of time, or even a sign of a person's time on earth coming to an end. However, it is important to note that this is just a superstition, and that there is no scientific evidence to support it.