Sure, if a toilet seal is leaking, or perhaps your bathroom sink faucet. This past summer, while cleaning the toilet, 'something happened' - not sure what but a seal in our toilet must have become temporarily dislodged. Walked out of the rig, heard the water pump running on/off, came back in and water was running out of the bathroom and down the hall. Our black tank was not full. Turned off the water pump, stepped on the toilet pedal several (many) times, turned the pump back on, stepped on the pedal many more times - all was well and continues to be well. Tried and tried to duplicate the problem but can't. Might not have even been related to cleaning the toilet but that's the only thing I could think of. Wondering if something similar happened to you? You didn't mention where in the bathroom the water was coming from? Was your toilet or sink leaking? Did your black tank fill up and overflow inside when the water pump was running? Is your water pump located in/under a cabinet in the bathroom area? Just throwing out ideas.