DIY Vintage Light Switch (Frankenstein Knife Switch)

Parts and Build:

I bought an antique knife switch off eBay as a decoration. When I got it in the mail, I knew I wanted to make it actually work. ?But I needed to make it safe. ?So I used a solid state relay and a phone changer to wire everything together. ?You can watch the process in the video above. ?I got everything to fit inside of the light switch box, so I didn’t need to drill into the wall.


1_knife_switch 1_parts_list 3_marking_size 6_circuit_board 7_wiring

11_mounting lights_on testing


8 thoughts on “DIY Vintage Light Switch (Frankenstein Knife Switch)

  1. Lucas

    I have been wanting to use a knife switch like this for a long time but couldn’t figure out the safety issue and don’t like the fake ones that just flip the regular switch. I know how to and have done electrical work around the house, adding lights and outlets, but know nothing about relays. There are a lot of different solid state relays, what are the exact specs for the one you used or just the exact item?

  2. Pete

    Hi Mike,
    great job! I was looking into relays as a way to use antique light switches safely at home. I found the relay you used on ebay and thought about a phone charger for the switch current, but wasn’t sure how to wire it . So cool to find your project online and confirm I’m on the right track! Can you show me how you wired it, a bit more clearly, as still not 100% sure.

    1. Mike And Lauren Post author

      Thanks! I updated the post with a picture of the wiring diagram. Hope that helps!

  3. Kyle Haugan

    What were the specs of the phone charger? Or is 5v the only part I should be concerned with? Great project!

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