Maybe a earthing spike for signal equipment?
I think the lugs have been cut off.....
" When you're chewing on life's gristle, don't grumble, give a whistle "
I think its some sort of locking pin, looking at the spike end it folds out to lock this in place
me too earthing pin.
I don't think it is an Erdstecker. None of the types I have seen have a pivoting point. It may be a radio antenna device. NH