I have an outdoor timer with two prongs (ie no ground). The wall outlet itself has GFCI. I have a three pronged (ie with ground) 3-outlet adaptor that does not fit into the timer as the ground prong hits up against the plastic/rubber enclosure of the timer. See photo attached (at top is the timer to go into the GFCI outlet, middle is the adaptor to go into the timer and at bottom the two-pronged extension cord). How can I string two or three extension cords (with either three prongs or two prongs) from the timer using the adaptor? I have not been able to find similar adaptors but with two prongs (ie without the ground) at my local stores.

enter image description here

  • Do the lights in question have two prongs on their plugs, or three? Commented Nov 7, 2018 at 2:15
  • you haven't busted off the round pin on that 3-way yet, so of course it doesn't fit... ;)
    – dandavis
    Commented Nov 7, 2018 at 21:58

2 Answers 2


Two-prong splitters are not hard to find. Expand your search to big box stores or online retailers.

You can also use the ubiquitous 3-to-2 adapter (cheater plug):

enter image description here

This adapter is safe to use in this case because of the GFCI outlet.

However, if you're in a pinch, just break off the ground prong on that green splitter and plug the ground holes on the outlets with caulk or something else non-conductive.

Don't use it for anything requiring equipment grounding. You're responsible for acting like an adult and not abusing this equipment (or a cheater plug, or whatever) or allowing less clever people to do so as a result.

  • It would work, but I don't like it. Someone who doesn't know better could plug a three prong appliance into the extension cord. It would be better to use a 3 prong timer, or a 2-prong splitter with 2-prong extension cords.
    – mrog
    Commented Nov 6, 2018 at 19:18
  • You'll want to downvote the 20 million people across the country who currently have space heaters and microwaves plugged into cheater plugs, too, not to mention all the broken extension cords hanging in garages. The difference here as that the intention is to only use it for ungrounded light strings.
    – isherwood
    Commented Nov 6, 2018 at 19:20
  • Yes, I would like to downvote some of those people, too, but only the ones that use the adapter plugs incorrectly.
    – mrog
    Commented Nov 6, 2018 at 19:21
  • 1
    convert the 3-prong splitter into a 2-prong splitter by removing the ground pin and filling all the ground pin holes with hot-melt glue
    – jsotola
    Commented Nov 6, 2018 at 21:53
  • 1
    No, because the splitter has polarized outlets but a non-polarized inlet after you break the ground off. OP needs to go buy a 2-prong splitter. Commented Nov 6, 2018 at 23:50

With a little DIY you can create a safe alternative than a cheater plug.

Find a box so you can mount the timer box and a few sockets into the side with the controls accessible without opening the box.

Find a cord with attached 3 prong plug. And one of more 3 prong sockets.

Connect the ground from the cord tot he ground of the sockets.

Connect live and neutral of the cord to the input of the timer.

Connect the output of the timer to the live and neutral of the socket.

The latter two steps may be easier if you cut the connection from the timer's plug to the timer and splice in there. Otherwise you will need to find a 2 prong plug and socket to make the connection.

Essentially you make the ground connection bypass the timer and run the power through the timer.

You can also add a relay to switch the live connection if the timer is on should you find that the power you need to switch exceeds what the timer can handle.

  • Thank you all. I did find a cheater plug - never heard of them before. A little harder to find here in Canada than in US maybe. HD for instance does not seem to carry them here.
    – Paul
    Commented Nov 7, 2018 at 16:11

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