Earth for oil pressure switch Disco TD5

After refitting my gearbox I was connecting up the electrical connectors and the one for the oil pressure switch the earth has come awey does any one know were the earth goes on the body?
Thanks

I think if were both looking at the same bit that it doesn't go any where, just got the engine out of my discovery and noticed a small black wire hanging out the loom 15cm down the loom from the oil pressure switch, but when you look at the oil pressure switch there isn't a contact in it on, why land rover left the teminal in the plug with a short peice of wire on the end not connected to anything i dont know.