Ask the super in your building if he knows if thats a beem he might know , i got the same thing in my apt and its not a beem ... make sure u will sleep better at night
I will ask the super anyways, see if he know which I highly doubt (He doesn't know anything) The only walls that are outside, one of them is a radiator and an AC next to it, one is the bedroom. and the other one is too small. But I'll ask around and see. Thank You..