You will need: a jar and glow-in-the-dark paint! First, take one of the jars and rinse it out. Next, take a paint brush and decorate the inside of the jar with polka dots of glow paint. Finally, go into a dark space and watch your jar glow!
DIY Yarn Wrapped Jam Jars - it's a good idea for the tunnel just to light the way. A solid row of these along the sides of the tunnel would be a good alternative to using whatever lights are built into it.