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Electrical Wire and Cable

How to Extend Electrical Wiring for a Light Switch

Wiring a Light Switch – How to Add Electrical Wiring for a Outlet and a Light Switch and Extending the Electrical Circuit Wiring for an Outlet and Light Switch.

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How to Add Electrical Wiring for a Outlet and Light Switch
Electrical Question: How can I put a junction box into the circuit wiring before a light fixture so I can add an outlet light and switch.


This electrical question came from: Jake, a Handyman from New York, NY.

Electrical Answer:
Dave’s Reply:
Thanks for your electrical wiring question Jake.

How to Add Electrical Wiring for a Outlet and Light Switch

Application: Adding Electrical Circuit Wiring.
Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrical Contractor.
Tools Required: Basic Electricians Pouch Hand Tools, electric drill, auger bits and extension cord.
Estimated Time: Depends on personal level experience, ability to work with tools and install electrical circuit wiring.
Notice: Installing additional electrical circuit wiring should be done according to local and national electrical codes with a permit and be inspected.

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Comments about this Electrical Project

4 Responses to “How to Extend Electrical Wiring for a Light Switch”
  1. Dave Rongey says:

    Hi Jerry,
    I understand your wiring problem and this may help you: If the added junction box will be accessible from the attic space then this method is allowed. However, if the junction box will be inaccessible then it is not allowed.

    How to Make the Wire Longer
    You may want to see if you can reconfigure the path of the cable by removing the cable staples, which may allow you to get a little more length from the wire so it reaches the new exhaust fan. Make sure the cable is well protected, and then secure the cable in place.
    Enjoy your new exhaust fan,

  2. Jerry Brown says:

    I am replacing a bathroom exhaust fan located in the ceiling. The existing electrical wire will not reach the new exhaust fan. Can I extend the wire by installing a junction box which will end up behind the ceiling dry wall?

  3. Dave Rongey says:

    Hi Albert,
    What you have described is known as a Multi-Wire Circuit, which is where two circuits from different phases or buss share the same neutral. You can tap into one of these circuits as long as the circuit has the available amperage and the neutral remains under the amperage rating of the circuit wiring conductor.
    Keep in mind that the circuit breakers that provide the power for these two circuits, circuits #6 and #8 should have a tie bar across the two breaker handles. The reason is because both of these circuit must be OFF before working on the circuit wiring to eliminate any voltage potential on the neutral wire.
    I hope this helps you,

  4. Albert Maruggi says:

    This is crazy I have two circuits coming into a 1 gang shallow outlet box, circuit #6 is on the top outlet. This is in the middle of a run as it goes to a junction box then another outlet. The hot wire from main panel, then the hot from the junction box share same pole. White to junction box on opposite of that pole.
    The bottom outlet has hot from main panel from circuit 8 and white from panel for circuit 8 plus a ground. It looks like then that this is a shared neutral.
    My question is how do I tap into this outlet for hard wire under cabinet lighting. It’s the most convenient source to get to. The next closest power source is the main room light which is on a 3 way switch. I am completely stumped.