WTF is this??

So I finally got around to taking down my Christmas tree today1 and as I packing up all the ornaments into the big Rubbermaid container I keep them in, I found this at the bottom of the container:

Does anyone have an idea what that is?  Because I’m totally flummoxed!   The two black rectangles at the bottom of the photo are strips of velcro – the white part is the backing on which they are stuck… so clearly they are supposed to stick somwhere and the corresponding piece of velcro are on the back side of those main thingy.  I’m not sure if the key goes with it or not – it was in the same plastic bag, but the bag was open so it could have just ended up there despite being totally unrelated.  Also, I don’t think it has anything to do with Christmas decorations, despite being in the Christmas decorations box.

Any ideas?

  1. In my defence, I was away in early January, when I normally would have taken it down []