Turn an old Geiger counter or CD meter into a prop, by adding an arduino and speaker to simulate clicks. I use a tilt sensor to activate that makes it hard for people to figure out what is happening.

How to identify the 220Ω 5-band resistor and 10KΩ 5-band resistor 5. Test Code Go to the folder KS3025 Keyestudio Raspberry Pi Pico Learning Kit Complete Edition\2. Windows System\2. C_Tutorial\2.