Hello ThisOnePerson,
It seems that you have been having some kind of fasciculation. This might be an initial symptom of localized epilepsy as well. Consult your neurologist for further course of action.
Best
Oh my! How dangerous is this? Will the lump go away?
I have this same thing going on.... Except my face is swollen in localized area and it twitching like heck. The area is about the size of a silver dollar. The first time this happened, it was the cheekbone area, this time it's under the eye and it's red and looks like I got hit.