Hi group..

There are seven of these sockets within a 1964 built house in Michigan USA:

"http://i60.tinypic.com/2628481.jpg"

Four in the corners of the living room, and three in the master bedroom.

I haven't had much success yet tracing where they lead to using a toner.
There doesn't appear to be any central point they all end up. Each one
has two solid core wires soldered to it on the back side. Looks like
they were installed with the original build of the house - the wires
from each seem to route through the walls.

I initially thought they were DIN loudspeaker connectors, but as you
can see the two contacts are both flat. The centres of the two contacts
are about 7mm apart.

Anyone know what they might be?

TIA