Those look to come from your Dynon or Garmin Glass EFIS wiring harness and they attach to the fuel sending unit mounted on your fuel tank that tells you what your fuel level is, electronically.
You should have a 6 or 7" diameter sending unit mounted towards the front side of the plane on your fuel tank, a big round ring of screws holds it in the tank with the float level sensor. One wire, the orange brown wire, is the hot wire and attaches to spade lug on the sensor, I would think, the other serves as a ground wire.