Commercial Fixed Wing
Flight Attendant Current
Deviation / Discrepancy - Procedural Security; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation; Flight Deck / Cabin / Aircraft Event Passenger Electronic Device
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem
Human Factors
There was an unclaimed vape in the aft galley on the counter that we believed may have belonged to either one of the cleaners; one of the caterers; or one of the people who did the security checks on the plane. Originally; [other flight attendant] thought it was mine and I thought it was his but when we found out it was neither one of ours; we disposed of it in the trash bin.  After realizing very soon (within a few minutes after putting in in the trash bin) that it was a bad idea to put it in there; we took it out.  We noticed that the light on the vape was flashing so we tried looking through the Operations Manual to figure out what we should do with the device.  After not finding any information on it; we contacted the purser who contacted the Captain who then advised us to put the device into the thermal containment bag. I was concerned with the vape flashing because I have seen it before where it would flash and start producing smoke. We were not comfortable with leaving it out and exposed.
Air carrier Flight Attendant reported an unclaimed vape device was left in the aft galley. After consulting with the Captain the device was placed in a Thermal Containment bag.