The fact that this was posted back in 2012 I doubt Valve are going to be adding this item. Yes the concept is good & most subscribed to this item want it in the game but at what point do we admit it might never get in now?

As for the question, if you've played around with it in the game workshop maps then you can see this in most places with the red light. You can hide it in certain places & not have it seen but then, like the teleports, if you find a position like that keep it hidden.