can any body tell me where this came from

Its hard to see in the pic but it looks like an SD computer

"SD" mean Speed Density.

Maybe I am just weird but did this just come out of the blue to anyone else. I know people ask to ID parts on here all the time but there is usually a reason behind it. Like someone replacing the rack and pinion and the rack bushings fall out or something to that extent....

What exactly are you looking for? If you are asking about the eec then the 88's (except Cali cars) came with an SD computer which is located underneath the passenger side kick panel. Some are upgraded to the mass air but your car should have it and it is nothing aftermarket that the previous owner added......