Last Updated January 2026

Whether you’re heating or cooling your home, small gaps where outlets and switches are set into drywall can let outdoor air seep in and heated or cooled air escape. Installing outlet and switch gaskets and sealing these gaps can help reduce air leaks and, according to the U.S. Department of Energy (DOE), lower your heating and cooling bills over time.

It’s important to note that insulating electrical outlets can be dangerous if not done properly. Risks include short circuits, shocks and fire. Consider hiring a licensed electrician to handle the job or consult a professional for advice.

Common causes of drafty outlets

• Older exterior walls without continuous insulation 
• Gaps where the electrical box meets the drywall 
• Outlets or switches located on rim or band joists 
• Missing or deteriorated foam gaskets 

Signs your outlets may be drafty

• Feel around the outlet or switch plate. Air temperature changes (cool in winter, warm in summer) signal a draft.  
• Hold a tissue in front of the plate. If it moves or pulls toward the outlet while your heat or AC is running, air is likely leaking. 
• Slowly wave a flame-free smoke pencil or stick of incense around the plate. If the smoke stream bends, air is moving through a gap.
• Look for streaks or smudges around the plate — signs air has been leaking and leaving fine dust behind. 

Materials and tools needed to insulate an outlet

Materials

• Foam gaskets (also called insulating pads) for outlets and toggle or rocker* switches 
• Acrylic/latex caulk or low-expansion spray foam 
• Electrical box extenders (if outlet or switch plates won’t sit flush) 
• Weatherproof exterior outlet covers 
• Painter’s tape (optional, for labeling) 

*Note the style of light switch: A toggle has a small lever; a rocker has a wide, rectangular paddle.

Tools

• Noncontact voltage tester 
• #1 and #2 (small and standard) screwdrivers  
• Utility knife  
• Safety glasses and work gloves 

Safety precautions

• Turn off the correct breaker and confirm the power is off with a voltage tester. 
• Do not use spray foam or caulk inside the electrical box. 
• Avoid overtightening cover plate screws — this can crack the plate. 
• If you see aluminum wiring, knob-and-tube wiring, heat damage or corrosion, you may need a licensed electrician to handle the repair. 
• Exterior installations may require weather-rated devices and covers to meet local code. 

A guide to insulating outlets

If the tops and bottoms of outlet and switch plates are not properly sealed at the time of construction, these holes can add up to a significant amount of air leakage, according to the DOE’s Office of Energy Efficiency and Renewable Energy. The following steps, adapted from the DOE’s Building America Solution Center, outline instructions for installing foam gaskets behind outlet and switch plates on walls to help reduce air leaks.

STEP 1: Prepare the workspace

• Find the breaker in the electrical panel labeled for the room or circuit and turn it off. 
• Verify the power is off using a noncontact voltage tester. 

STEP 2: Remove the cover plate and inspect

• Remove the wall plate from the outlet or switch. 
• Inspect the area. Scorch marks, melted plastic, loose wiring or warmth at the outlet or switch could be a sign of a serious issue that requires a licensed electrician, according to the Building America Solution Center.

STEP 3: Install the gasket

• Match the gasket to the outlet or switch. 
• Make sure the gasket fits by holding it over the outlet or switch so the openings line up with the receptacle slots, switch toggle/rocker and screws. 
• If the gasket overlaps the opening or plate area, use a utility knife to trim the edge so it sits flat without covering slots or interfering with switch movement. 
• For GFCI outlets, press the “test” and “reset” buttons after the gasket is in place to confirm that the openings do not restrict movement. 
• Press the foam gasket flat against the drywall opening, centered over the electrical box.  

STEP 4: Seal the box-to-drywall gap

• Apply a thin, continuous bead of acrylic/latex caulk or spray foam around the outside edge of the electrical box where it meets the drywall. 
• If using spray foam, apply it lightly in short bursts around the box perimeter. The foam will grow as it cures, and too much can push on the outlet or switch. 
• Allow the sealant to cure according to the manufacturer’s instructions before putting the plate back on. 

STEP 5: Adjust wall plate fit with a box extender

If the plate no longer sits flat on the wall after sealing, you may need an electrical box extender to maintain proper spacing and support safe installation.

• Choose an extender depth that matches the gap between the front of the electrical box and the wall surface. 
• Loosen the mounting screws that hold the outlet or switch just enough to slide the extender over the outlet or switch and into the box opening. 
• Gently retighten the mounting screws so the outlet or switch and the extender sit flush with the wall, without twisting or tilting. 

STEP 6: Reassemble and test

• Reinstall the outlet or switch plate. 
• Flip the breaker for that circuit back to the ON position. 
• For a GFCI outlet, press the “test” button. When it clicks, downstream outlets on that circuit will stop supplying power. Press “reset” to restore power. Or plug in a small lamp or use an outlet tester to confirm the outlet turns off with “test” and on with “reset.” 
• Retest for air movement with a tissue or smoke pencil near the plate.  

STEP 7: Insulate exterior outlets

Exterior outlets need special care due to moisture, temperature swings and exposure. Here’s how to insulate an exterior outlet to help limit drafts.

• Use weather-rated gaskets designed for outdoor use. 
• Contact a licensed electrician if exterior outlets are not GFCI devices (no “test” or “reset” buttons), as required by the National Electric Code^®.  
• Install a weatherproof “bubble” cover that closes fully around plugged-in cords so the outlet stays protected when it’s in use. 
• Avoid blocking any drainage holes — moisture needs a way to escape. 
• If the box is metal, confirm the cover and gasket materials are approved for wet locations. 

Other ways to support energy efficiency at home

Insulating drafty outlets is one small way to help make your home more comfortable and energy efficient. These projects and regular maintenance can support major systems like your heating and cooling equipment and may help you avoid potential problems down the road. Explore more seasonal home maintenance tips that can help you conserve energy and save on repairs.

The information contained in this page is provided for general informational purposes only. The information is provided by Farmers^® and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to this article or the information, products, services or related graphics, if any, contained in this article for any purpose. The information is not meant as professional or expert advice, and any reliance you place on such information is therefore strictly at your own risk.

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