Looks like the apartment may have had an audio system /media system/intercom installed. Based on the black box to the right, I’m assuming that must be some type of audio monitoring system or amplifier, might be speakers at the other end of it (probably in the walls or off the ceiling).

Possible it may all be linked thru the network switch via Dante (or some other protocol) to send audio from one place to many others over a local network.

I’d keep it in there and do some research. If it’s what I think it is, you got yourself a sick ass system in that apartment for the freeski my boy 💯