Though it may look odd, this problem is not all that uncommon. Inside the walls of your house, bathroom, your tub, sink and shower are all connected to the water supply pipes. A problem with one faucet can be related to pipes resulting in another part of the bathroom. Each is linked to the main water line in precisely the same manner. Then the toilet faucet drip is caused by water pressure when the toilet is flushed if your faucet flows. The water pressure from the water supply line has exceeded 80 psi. Whenever your toilet is flushed, water flows to refill the tank.