On a different board I stumbled across a question concerning a very odd old (probably pre-WWI) electrical connector. It looks like a male NEMA 1-15 connector recessed into the baseboards of a 1912 house. Anyone got an idea what that might have been used for? http://www.oldhouseweb.com/forums/viewtopic.php?f=5&t=25272
I have seem recessed male power plugs used as power inlets before. Are these connectors adjacent windows? I remember seeing a thread about lighting outlets built into window sills. Perhaps these were built in extension cords for remote lighting outlets?
Although the house is quite old, you might be looking at younger work -- say the 1920s.
Way too early for TV these might be RADIO antenna taps for a home trying to pick up signals with an exterior master antenna.
Back in the 20's commercial radio was high tech. Many broadcasters had weak signals. It was common for the local station to have such a weak signal that fifteen miles would be pushing it!
Now the radio boxes were obviously limited WRT size of antenna. A receiver outside the home which piped in the signal was like Direct TV today.
Since the signal would be captured as a dipole and low voltage, at that -- this kind of tap could be retro-fitted at will in base board. The male outlet style was used so that the connection to the radio would never, ever, ever get jacked into power.
The multiple locations exist for interior decorating reasons. OF COURSE the radio -- the ONLY entertainment box -- is going to be located solely in the living room. However, the lady may change her mind. So the retro tech provided her with a wall or two of convenient taps.
All he had to do was pull off the existing base, pop some small holes, fish wire ( no conduit, not even Romex ) and then punch some inlet holes.
Wham, bam, thank you, mam! That antenna string is installed! That'll be $4.25... please refer me to your circle of friends.
My eighty-five year-old father confirms that this is what he saw as a child, and the antenna WAS outside the house.