2019 Pilot found on the floor, center row right seat. A brass adjustment type of screw, 1 1/8 inch long by 1/4 width at threads. Pointed at the tip and designed to be hand tightened. Can't seem to locate where it came from or find a parts schematic that lists it. Looks to possibly be for setting fluid flow as it has a light bluish corrosion. Perhaps the rear air???

 

It is not a car part. From some other trinket that was transported in the vehicle.

 

Ryan,
Thank you, I thought the same but figured it wouldn't hurt to have others chime in. I'm pretty handy mechanically but it stumped me. It is my wife's car and she has not had anything in there that it could have come off of she says. Oh well!
Take care my friend.