This is a super simple Christmas tree light switch. Because where you plug the tree in is NEVER handy to get to. You could buy one, even a remote one -- BUT -- why do that when you can DIY.
Step 1: Materials
I had all this laying around. I'm kind of a pack rat. I used an extension cord, an old pill bottle and an inline replacement light switch. The pill bottle will "house" the connections that will be made. You can come up with other 'containers' that will satisfy that need. The important things are that the container is insulated (plastic) and that it is secure.
The one weak link in this is the light switch. Make sure it will handle the amperage you're going to put through the outlet(s). Don't load it up -- Use your head. I'm not responsible for anything stupid you do. This project is with live AC mains and the voltages are lethal. And of course if you overload the amperage rating of the switch it will overheat and cause a fire. Not exactly the perfect Christmas ending...
Step 2: Cut the Cord...
You need to cut the cord and decide how long you want each piece to be. You need to base the length on the "box" you will stuff all your connections into (in my case it was a pill bottle). You can use a small plastic box or anything that will be insulated and secure to hold the connections.
The plug end becomes the part you plug into the wall
The socket / extension cord end becomes the part you will plug all your Christmas lights into.
The the remainder of the extension cord becomes your remote cord to the switch -- so size accordingly. Pick a longer extension cord if you need a longer remote...
One thing you do need to be aware of - there is a polarity to AC outlets and cord. Basically the wide blade of the plug that goes into the wall is the neutral line. The narrower blade is the hot line. You should ALWAYS switch the hot line, not the neutral. This WEBSITE is a good basic introduction to walk you through this. But if you're not comfortable doing this -- Don't DO IT!
You will notice that the extension cord has some ribbing on one of the wires. On my extension cord that ribbing was on the neutral side. Verify that with your cord. I don't know that there is any standard on that and I don't want you to do something stupid.
Step 3: Make Some Connections
I tinned the ends of my 'remote' wire (tinning - solder on the end of the wire to make better connection and to protect the wire). I then screwed the end of the hot wire coming from the plug to the RH side of the switch. The LH side of the switch the 'cold side' when it's off is the return. That goes back to the pill bottle...
Step 4: Close the Switch
I then closed up the switch -- because my extension cord insulation was so heavy, I had to 'trim' some of the plastic to get the switch to close up with the screws. You want it all closed up so it is safe. Read the instructions that came with your switch. The end where the cord would go on through when used "in line" could be closed up with a dab of hot glue or silicone. Since my wire wrapped around there it basically closed the hole so I didn't bother with it.
Note: you could even use a plastic switch box on this end and a regular light switch if you wanted -- though that would be a little harder to hide. Or be creative and hide the switch in something or decorate the switch box to blend in with your decorations.
Step 5: More Connections
Drill your pill bottle (or whatever you're using) and push the wires through. Plan this out so you don't have a jumble that is hard to get into your container and hard to insulate well -- that's important. Protect the connections!
Oh, and don't forget to push the wires through BEFORE you make the connections. I soldered my connections and then sealed them with heat shrink tubing and with one -- heat shrink tubing & electrical tape. You could use solderless connectors or twist on connectors. Just be sure they are secure and insulated from each other.
I soldered the neutral wires together.
I then soldered the hot from the plug TO the switch.
Then I completed the wire FROM the switch to the outlet taps.
Heat shrink and tape everything nice and tight.
Then I took and attached a nylon "zip" tie around the wire bundles on each side to keep the wires together, and also to act as a strain relief to keep the wires from pulling back through the pill bottle hole -- just in case the dogs and cats would decide to play tug of war with it! Normally something like this I would have painted the pill bottle -- I left it 'clear' so you could see it better.
I always test my work -- I use a ohmmeter set on continuity mode to check out the cord - to make sure the switch works, that indeed the hot wire is being switched and to make sure the wires are not accidentally shorted together.