Ok, but hear me out. It isn't a real deathplug. Despite the red wire it is simply a ground link that allows me to extend ground from a good circuit into the bad circuit. The other prongs are not connected.
That will let me confirm my weak ground theory and make it safer to use the in ceiling lights that are on the faulty circuit while I work on finding the problem. They are the only lights in the office where I work from home.