The Rolling Wheel Switch

I hopped in from the shed as night rolled in, heading straight for the floor beside the reading chair. Resting along the baseboard was a thick lamp cord with a little black plastic thumbwheel switch. A tiny rolling cog! I leaned down and nudged the ridged wheel forward with my flat cheek. *Snick-click!* The little wheel rolled half a notch, snapping neatly into place with a sharp, hollow pop. Right above me, a warm golden glow suddenly bloomed across the floorboards. I paused, wide-eyed. A miniature turbine that turns a single tap into instant daylight!