is it possible to add a light to a three way switch circuit between the two three way switches (ie can i tie into the three wire connecting the two switches in anyway to make them work the new light I've added)?

  • 1
    No. The lights can only be controlled by the common terminal on one of the switches. Connecting the light to one of the travellers, will cause it to only be controlled by a single switch.
    – Tester101
    Jan 21, 2013 at 17:34
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    The trouble is basically all 3-way circuits use a 3-conductor wire (take a look at some 3-way circuit diagrams). You always need 2 travellers, and so the other wire is either a neutral or the switched hot (and in the case of the light between the two switches, on one side it's switched hot, the other side it's neutral). The only way it would be possible is if you have a 4-conductor wire between the two switches or run a new 2-conductor wire (either between switches or to the new light).
    – gregmac
    Jan 21, 2013 at 17:39
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    The other option is to go to "smart" switches, such as Insteon, Z-wave, or UPB. With these, the switches communicate to each other using a separate carrier signal (either wireless or over existing 120V lines). Effectively any "smart" switch/keypad can control any other "smart" switch/bulb/module from anywhere in the house. If you go this way, you'd have to replace both switches with smart switches, and your 3-conductors between the two become hot, neutral and switched.
    – gregmac
    Jan 21, 2013 at 17:43
  • Tester101, I think your comment is the answer. If you entered it as an answer, I would certainly vote for it.
    – skiggety
    Sep 6, 2014 at 0:35

2 Answers 2


If you tap into the existing light box: Yes There you will have the switched power and neutral. If you try to tap into the triplex running from one of the switches: NO. There you will only have the travelers and a power.


Yes if you don't need the three way functionality still and one of the boxes has power coming into it. You can put a blank on one box, put your new one in-between, and keep one box for the current light switch. I don't want to get into the wiring on this because it is simple (get rid of your 3-way comms wire - red one) and make sure your power/neutrals pass through, but there are tons of ways that 3 ways can be wired so don't want to get into too much detail.

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