It sounds like you’re starting to write a short, humorous, or mysterious incident report. Based on your fragment, here’s a completed version in a standard report format:

A weird noise was reported coming from the men’s toilet. The sound was described as [e.g., rhythmic tapping, low humming, intermittent gurgling, faint scratching, or a mechanical whir]. It does not resemble any normal plumbing or ventilation sound typically heard in the facility.

[Insert date] Time observed: [Insert time] Location: Men’s toilet, [specific building/floor] Reported by: [Your name/role]

The toilet was visually checked from outside; no visible cause. Upon entering (after announcing presence), the noise briefly stopped, then resumed after ~30 seconds. No one was inside the stalls at the time.