Q: I went to use my hairdryer in the bathroom, but I discovered some of the outlets have stopped working. My GFCI test button won’t push in when I try to reset it, but nothing has tripped in the ...

Person plugging something into a GFCI outlet with red and black buttons - Tomsmith585/Getty Images Have you ever noticed how some electrical outlets in your home look slightly different from the rest?

Q. We just bought an old house, built in the 1950s, so the electrical outlets are not grounded. We'd like to add GFCI outlets near the bathroom and kitchen sinks for shock protection, but our home ...

Once again we’re trying to dispel a modern mystery that lurks in plain sight. For previous columns, click here; to submit your own suggestions, see the e-mail address below. Who indeed? Next time ...