Wire off speedo drive gear?

[demonpixel]

We are getting very close to getting my 72 Firebird fired up today. I am about to put in the driveshaft and I saw this; does anyone know what this wire goes to?? Is it a ground wire? It looks like a tab connector but I have no idea what it's for:

https://static1.pt-content.com/images/pt/2010/10/speedo_gear_wire-1.jpg

Thanks for any help/advice!

[shep]

Just a wild guess could it be for a speed warning indicator?

[newvintageusa]

Cruise control output, can also be used for an electronic speedometer
Mark from New Vintage