I was rearranging stuff in my basement and found a strange looking receptacle. It is on a 15A circuit in an 1950s house. It is in a room that I suspect (for a bunch of reasons) was finished by the owner rather than the builder, probably in the 1960s or 1970s.

strange looking receptacle

And now, finally, after more than a year, I have gotten around to replacing this. Good news (as with the other 3 I replaced today) - grounded metal boxes so self-grounding Leviton Commercial grade worked perfectly. Bad news - while all the others I replaced were "normal" (one or two black/white), this one had three black on hot side, 2 white and 1 one black on neutral side. I wired up everything the same as the previous receptacle, and everything else on the circuit is fine, but it does leave me wondering a bit. My hunch is that this was a homeowner special with a spur (black/black!) to another receptacle in the same room that I haven't gotten to yet.

And now replaced 2 more in another room. They had hot/neutral reversed! But in a daisy-chain, so one showed reverse with a magic 8-ball (cheating on ground) and one showed normal. Arggh! Replaced them and I feel much safer now. Plus these last two were in shallow/narrow boxes (but in the open, so easy enough to replace) so the new receptacles don't fit in all the way, so a bit more shopping in order. But at least hot, neutral and ground are all wired properly. And I am now sure I need to carefully check anything/everything done by the previous homeowner. I've been here a long time and never really looked into this stuff, but I've learned a lot from Harper, Ed Beal and the rest of you. The adventure continues...

  • 4
    It's a very naughty one because it can accept plugs now designated for either 120 or 240. Apr 1, 2020 at 20:08
  • 2
    Can't say for sure, but I imagine this was some kind of... transitional outlet when they were still standardizing outlets for 15A, 20A, and 220v...
    – JPhi1618
    Apr 1, 2020 at 20:09
  • 3
    That house-incinerator is the ancestor of the house-incinerator I found! Apr 1, 2020 at 20:31

1 Answer 1


It's a plug that accepts Hubbell's 1906 tandem and 1912(?) parallel plugs. Both were rated for a maximum of 250v, but usually wired for 120.

Similar rating to Edison 1" (now called E26), most are rated for up to 250v, but we commonly see them used only for 120v.


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