To skip to the videos of the nightlight in action, click here!
Update: I received many complaints about the aesthetic quality of the pull chain nightlight's installation and several suggestions that I should place the circuit in the diffuser bowl. Well I'm pleased to announce that I've reworked this project to keep the circuitry out-of-sight and make the pull chain wiring look better. Steps 1 through 5 describe the rework as if I started from scratch, and steps 7 through 10 are the original instructable.
The primary source of illumination for my bedroom is a ceiling fan lamp. Most of the time I use the wall switch to turn the light on and off, but sometimes I'm closer to the pull chain switch so I'll use it instead. The trouble is the pull chain can be impossible to find in the dark; sometimes I'll find it right away but other times I'll flail my whole arm around feeling like an idiot trying to locate it. So I decided to hack apart a solar powered garden light and use its LED to make the pull chain's handle glow. When the garden light circuit detects the ceiling fan lamp is off it powers the LED with a battery. The circuit also recharges the battery when the lamp is on via a solar cell.
Step 1: Disassemble the Garden Light
Solar Garden Light -- Portfolio Stainless Steel Solar-Powered LED Path Light (Item #: 329346 | Model #: 00942)
Pull Chain with a Translucent Handle -- Harbor Breeze Brushed Nickel Ceiling Fan Pull Chain (Item #: 101858 | Model #: FP5)
Enclosed 2x AA Battery Holder -- Radio Shack 278-502
~30 in (~75 cm) of Wire Wrap Wire (30 AWG) -- Radio Shack 270-408
A piece of Scrap Copper Sheet Metal (about the size of a battery contact)
Heat shrink insulation or Sewing Thread
Hot Glue Gun
For this instructable I used this garden light. First I separated the end that held the globe and electronics from the metal tube and removed the battery. Then I removed several sets of screws to separate the electronics from its housing. Next, I gently pried the hot glued photoresistor from it's mounting hole, and then removed the excess hot glue. I used diagonal cutters to snip the battery leads where they met the battery contacts. Then I cut the LED's wires so I could insert it into the pull chain's handle in step 4. Finally I desoldered the solar cell so it could be taken out of its plastic holder.