From: nobody@home.invalid   
      
   I have an old (1940s I think) ceramic outlet in a box, for a two prong   
   plug, no ground. It accepts a standard US 2 prong (1-15) plug. It is   
   polarized. It is also marked "15A 125V" (molded in the ceramic).   
      
   The box also has 2 standard fuse holders, one in series with each slot.   
      
   However, both slots are T-shaped, like one slot is in a 5-20 or 6-20   
   outlets. Almost as if it was designed to accept a 2-15 plug (does such a   
   thing exist?) as well as a standard 1-15 plug.   
      
   Why are the slots T-shaped?  Were 2-15 plugs a thing for 220V at the   
   time, they installed the same outlets on both 110V and 220V circuits,   
   and you just had to know which outlet to plug in the 110V things and   
   which to plug the 220V things in? And if you got it wrong, too bad?   
      
   That's what I thought when I saw these in older houses. But this one is   
   explicitly marked for 125V max, so it's not intended for 220V.   
      
   For a 110V circuit, one fuse would be in series with the neutral, not a   
   good idea. But it would make sense if used on a 220V split phase circuit.   
      
   Why are the slots T-shaped?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)