Instructions
Rip or cut out a piece of paper just shorter than the length of the comb but two times the height of the comb.
Fold the paper in half. Slide the folded side of the paper over the comb's teeth.
Put your lips up onto the paper and hum. The vibrations from the paper transfer to the comb and give out the kazoo buzz and hum.
Experiment with wax, tissue, wrapping or other paper types to get different noises and tones.