I found this outside below the meter with a sub panel in the living room. Is it a disconnect?
It is the disconnect.
If it’s between the meter and the panel then it’s the service disconnect. The neutral should be bonded to the enclosure at that point. Since there are only three conductors on the load side of the disconnect the conduit would need to serve as the equipment grounding conductor. There should also be separation between the EGC’s and neutrals at the sub panel.