When you see water stains on the ceiling, together with plastic Tupperware, you know there’s likely an active roof leak!  Of course, I use very expensive equipment to confirm (e.g., moisture meter and infrared thermography camera), but this one was obvious.  With water intrusion, there’s always the possibility of underlying damage not visible without invasive inspection; it wouldn’t hurt to open the ceiling and look for possible mold growth.  This was discovered at a recent home inspection on Orcas Island in the San Juan Islands.