Pawnee bladder ground?

Hey all. Removed sight gauge/filler cap assembly from Pawnee to change fuel bladder. It has a (ground?) wire hanging off it, looks like the terminal broke off the other end.

Parts catalog doesn't show this.

Anyone know where that end is supposed to attach? Bolts that hold the assembly on are all thru glass/cork/rubber...doesn't seem like it would serve as a ground there.

Is it possible it goes to the filler neck to wing structure as a static electricity ground when fueling? Granted, the fuel hose nozzle usually connects to the plane for static discharge.

Mystery solved. Runs from firewall thru fibreglass shell to sight gauge. Lays over top of bladder.

To clarify, it is embedded in the fibreglass. Part of the glass tank so it doesn't show in parts catalog.