Took me 4 hours to figure out a customer's PC kept waking from sleep, it was an Xbox controller
Client in Denver called saying her tower would wake up at 2am almost every night and the fans would blast. I checked power settings, pulled every USB device, swapped the PSU, even ran a wake timer audit in cmd. Turned out her kid left a wireless Xbox controller plugged into a charging cable on the desk, and the stick drift kept sending input that woke the machine. Ever run into a wake-from-sleep ghost like that? What was yours?