GHOST FLUSHING TOILET
Ghost flushing happens more often than you think, and no, you do not have a ghost who uses the toilet and then is kind enough to flush.
The two most common reason’s for this are..
(1) You need a new Ballcock or Flapper. Usually the flapper inside the tank is not tightly sealed and the toilet tank is leaking water into the bowl, and needs to be replaced. This should take care of your Ghost flushing.
(2) Time to check your water pressure at the Hose-bib that’s located after your regulator. If the water pressure at the hose-bib is much, check your regulator. If the regulator shows pressure above 80psi than the force of the water pressure can break the seal of the ballcock. Not only do you need to replace the ballcock, you will also need to look into having your water pressure regulated.