Using a standard fluorescent tube lamp (TL), you can make your own disco light, similar to a stroboscope light. You can even use a half-broken lamp, which one side of the heating filaments has broken. This circuit use only one side heating filament inside the tube. Look at the circuit’s schematic below.
Please be aware that this circuit uses high voltage from your main power line, can be very dangerous. Although the control circuit uses 12 volt supply, it isn’t isolated from the SCR driving the high voltage. The only isolation is the audio transformer connected to your audio amplifier.
R1: 470k; R2:100k; R3:3k9; R4:18k; R5:10k; R6:2k7; R7:33k; R8:1k; R10:2k2; R11:2k2; P1:10k; P2:10k; C1:0.1uF; C2:10uF/16V; C3:47uF/16V; TUN: 2N3904 or BC547.