nerve spit
When someone far away, say ten feet, is talking and you feel something like a drop of spit on your arm after they overdictate a syllabal. You go to wipe it off and there is no spit-only your nerves playing a trick on you.
Mrs. Hill was talking about Egyptians in History class and I dozed off. I woke up to a small tingly sensation on my arm after she said, "pyramidssssssss", but it was only the nerve spit.