Condensate
Not every indoor drip is domestic water.
A blocked condensate line overflows at the air handler. The stain can sit under a bedroom ceiling and look like a pipe. Summer makes this more common, not exclusive.
Ask whether cooling was running.
A leak that only appears on hot days with the air on is a condensate suspect.
The overflow pan is a clue if you can see it safely.
A rusted pan or a wet air-handler closet points at condensate, not copper.
Dirty water versus clean water.
Condensate is often clearer than waste. It is still water damage.
Questions people ask
Is this a plumber or an HVAC tech?
Clearing a condensate line is usually HVAC. If the source is not yet named, a water investigation can still be the first visit.
Can condensate wet the suite below?
Yes, if the air handler sits over another suite.