Replacing a ceiling fixture in a house (1989); removed the old fixture, which worked perfectly fine, but now I see up into the box there are 3 cables to this box that includes two blacks and one white that are pigtailed, as you can see in this short video clip. I am thinking this qualifies as a TAR (That Ain't Right)?

Should I be calling in the big guns, or can I sleep at night with this scenario, if I just connect the new fixture as the old one was installed?

  • 5
    Hey, @TomTom. Thank you for contributing here! I've noticed in both of your questions, you've included a video clip. Thanks for that effort! We generally prefer pictures here though because StackExchange keeps a copy of the pictures. This helps retain the information in the post if for example, you delete those videos from your Google Drive or your Google Drive hits its bandwidth limit for the month. Some situations do need a video though and that is perfectly understandable. Nov 3, 2016 at 17:30
  • Makes sense @Zach Mierzejewski. Thanks for the tip.
    – TomTom
    Nov 3, 2016 at 21:33

3 Answers 3


It looks like an inline switch to me, which is usually indicated by a mark on the wire. Are there any black markings (Eg sharpie or electrical tape) on the white wire? You should be able to wire in your fixture to the old wires exactly as is.

inline switch

  • 6
    +1 The third cable probably carries current to another fixture or outlet. Black on black and white on white. If the white wire pigtailed to the blacks does not have a mark, do it now with a black marker or electric tape to help next time.
    – bib
    Nov 3, 2016 at 16:16

I have a 1950's house Pennsylvania (USA). I have found some strange wiring like you describe.

Undo the wire nut, separate the wires so nothing is shorting or touching, and turn the power back on. Then see what doesn't work.

I have found the often the "extra" wire is feeding power or ground to an outlet or another light. In my cases there was 3 strand wire going to the light from an outlet to the light to another outlet.

The first time I found it I disconnected the light in the garage and found it also feed power to the outlets in the bedroom above.

  • I am thinking the strand feeds the smoke detector located a few feet away, as that was also disabled when I shut off the breaker that controlled the fixture. I would have thought Smokes would be on their own circuit, but I just bought the house, didn't build it. Many thanks!
    – TomTom
    Nov 3, 2016 at 21:43

So you have 3 wire sets here

  • A line-in (from the circuit breaker or previous light fixture on the circuit)
  • A line out (to the next light fixture in the circuit)
  • A light switch

Just as a general FYI, you normally will have 2 line wires run to switches. So, for instance, it looks like you have a switch on the hot(black) wires. Because the wire in the wall to the switch will have a black and a white wire, you will want to hook the white to the black wires. It sounds backwards, but the logic here is that, when the current comes back through the wire (i.e. you flip the switch), you want to be able to hook it to the right wire (not terribly important for a basic light fixture, but a lot more important for, say, a ceiling fan).

In other words, it would be completely confusing if you pulled the fixture off and found it wired into two white wires. You would have to figure out which was the neutral and which was the switched hot.

Just hook it up as you're thinking. Black to black, white to white and your ground.

  • Thanks @Machavity. I did just that, and many lumens are now awash in my hallway. I did notice on circuit breaker panel that the notes indicate "Ceiling Lights/Smoke 1" and when the breaker was off when I was working on it, the smoke detector installed 3 feet away was also lacking power. Again, a 1989 dwelling, but better than a 1929 dwelling.
    – TomTom
    Nov 3, 2016 at 21:40

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