Unstick a drawer
If you have a desk or chest drawer that sticks, remove it and rub a candle on the runners. The drawer will open more smoothly when you slip it back in place.
Make a pincushion
A wide candle makes an ideal pincushion. The wax will help pins and needles glide more easily through fabric too.
Quiet a squeaky door
If a squeaky door is driving you batty, take it off its hinges and rub a candle over the hinge surfaces that touch each other. The offending door will squeak no more.
Make a secret drawing
Have a child make an “invisible” drawing with a white candle. Then let him or her cover it with a wash of watercolor paint to reveal the picture. The image will show up because the wax laid down by the candle will keep the paper in the areas it covers from absorbing the paint. If you have a few kids around, they can all make secret drawings and messages to swap and reveal.