What is this doorframe attachment?

Every door frame in this house had these little plastic tubes screwed in to the top of the door frames. They don’t seem to serve any purpose (they don’t have any effect at all on the operation of the door). Anyone seen these before? Were they part of some other assembly that has been removed?

security system door contacts

I had considered something like this, but they are only on INTERIOR doors (including laundry, bathrooms, walk-in closet, etc.). Does this make sense?

Are they on the jambs.

Maybe some sort of packaging items left on the door frame? Never have seen it before.

Thanks guys for all the replies I’ll try them very soon!


Those are leftovers from baby-proofing door lock mechanisms I believe.