This usually indicates that water is constantly running into the overflow tube. This happens because the float is set too high, or the fill valve is "leaking" and cannot shut off completely.

Strange noises from a toilet are rarely an emergency, but they usually signal that a specific internal part is worn out, dirty, or under too much pressure Identifying the Sound Whistling or Squealing

Appendix A: Audio spectrogram (attached separately) Appendix B: Thermal image of Stall 3 wall (attached) Appendix C: Witness statement transcripts (confidential)

Perhaps the most unsettling is the "Phantom Flush"—the sound of a toilet refilling in an empty room. It’s not a spectral visitor; it’s a slow leak from the tank into the bowl, forcing the valve to top itself off every ten minutes. When the Mundane Becomes Memorable