Oil Pressure switch

I can't seem to find the correct term for that oil sensor plug that lights up in the dashboard if the oil level is low or what ever...is this it? Also mines is leaking oil where it plugs into (right above the oil filter of a '99 protege ES) I'm curious to know how hard is it to replace this problem? thanks!

The switch above the oil filter is the sending unit for the low oil pressure light.

.....lights up in the dashboard if the oil level is low....

That describes a low oil level light, I don't think the '99 came with that option but I'm not sure.......Mike