Glad to hear you found and corrected your problem. I'm going to tell my story anyway.
A friend bought a new S&B home. They lived there for almost a year when they decided it was time to clean the windows. DW is outside standing on the wet ground, hosed a window with the garden hose and then touches it with a wet, soapy sponge. BAM, she got the shock of her life. Unharmed but sore and shaken, they call the builder to explain the situation.
The next day the builder sends out a handy man repair guy. He knew exactly what the problem was. He rips out a section of the interior drywall under the window to uncover a screw used to set the aluminum window penetrating a romex running under the window, coming in contact with the hot wire.
That has been sitting there waiting to be discovered in a violent manner from day one. The handy man didn't seem to be surprised and played it down as "it happens".