Built the housing last night by slicing off a thin piece of a small log, then routering out a place for electronics and battery in end of log. A hole through the top for LED and another through the side for the pusher rod for the button. Made a linkage from the rod to the button with heat shrink tubing. Then screwed down the thin piece of wood as a cover on the bottom.
LED charges glow-in-the-dark mushroom. Shroom becomes nightlight for a few hours, gradually fading to dark.