Removing the fuel filter housing, but what is this behind it?

[Iaitoo]

Changed the fuel hoses and put in a TT filter today, so thought I'd just remove the old housing (Nothing that has to be blanked off under there, right?).
But what is this plug that goes in to the housing? Will the car be sorry if its not connected? Or is it just the water in the fuel filter housing sensor?

[Frosty]

Just leave it unplugged will be fine. Its for the water in fuel light on the dash. The light will stay off when disconnected.

[Iaitoo]

Thanks It comes on and turns off all the time, so thats good.