oil send switch? 420a location?

ok so i have the haynes manual but i cant find it anywhere to be found. is there anyone who can tell me more exactly where it is? the mechanic said on the back of the motor but there are a lot of things. mostly electric looking. so is this an electric part and if so...can it still leak oil?
thanks this car wont get the best of me...ill see it working again if it kills me...which it might lol