Help with part identity needed!! Options

[Booztd 3]

Hey guys. I noticed my oil pressure dropping rapidly on the way home the other day, i pulled aside and put some more oil into it and limped it home, only to figure out the piece pictured below had a hairline crack and was leaking oil. By the time i got back to look at the car (an hour or so later) all of the oil had leaked out, nothing was on the dipstick!! I reached up to touch this part and snap, it just broke off like that (and the threads are still in the housing)



My question is....what the hell is this piece? I tried finding something similar to it at autozone with no luck, they only carry the oil temp sending unit. Am i going to have to order this from mitsubishi exactly or what? and how am i going to get the rest of the threaded fitting out of the housing. I tried using an extractor but the broken off stud is just too tight, so for now i just tightened the extractor down and thats what is plugging the hole I have figured out that the pressure sending unit has the same size thread so if i can manage to get the rest of the stud out of the housing i can at least plug the hole with the pressure sending unit, and besides i dont like driving around with my oil pressure guage on 0!!!

Thanks for the help if provided, and if any of you have that piece sitting around or in a parts car you might have i'd be glad to take it off your hands!! Thanks