This was decades ago, so I forget the exact details, but the story goes something like the following.
In high school electronics class we built a simple RC circuit that made a small neon bulb flash. I modified my project so that the circuit triggered a power SCR or triac. I put the whole circuit in a hobbyist box that plugged into the wall, and put an outlet was in one side of the box.
While my mother was out, I plugged her bedside lamp into the box. She came home, turned on her lamp, which immediately started blinking, and said "George! Come quick! My light is going to explode!"
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