Mystery pipe

We're combining two coop apartments and found a pipe in the wall that was between the two apartments. The super doesn't know what it is and the building engineer was no help at all in trying to identify what it is. It appears to be an electrical riser, but it's nowhere near the risers in our two apartments and we know where the risers are in every apartment in above ours, none of them really make... [more]

We're combining two coop apartments and found a pipe in the wall that was between the two apartments. The super doesn't know what it is and the building engineer was no help at all in trying to identify what it is. It appears to be an electrical riser, but it's nowhere near the risers in our two apartments and we know where the risers are in every apartment in above ours, none of them really make sense. There's a hallway lamp in the floor above ours that's close to this pipe, maybe it could be for that. I suppose it could also be internal to one of our apartments, but it doesn't look like it, since it appears to go straight up rather than bend. Our electrician contractor says we can't open up the pipe without risking taking out a neighbor's power (makes sense!), but no one is coming up with a suggestion as to how we identify what this thing is. Any thoughts would be appreciated! [less]