Learn how to safely modify and improve a fan speed controller with an integrated digital voltage and current display. Examine the disassembly process, identify potential safety hazards, and implement necessary modifications to ensure proper functionality. Explore PCB manufacturing options, test the modified controller, and understand the digital panel display features. Gain insights into pricing considerations and key takeaways for working with mains-operated devices in this informative 27-minute video tutorial on electrical safety and DIY electronics.