PC randomly wakes from sleep

[Malevolence]

I simply cannot figure this one out? If I put my PC to sleep there are occasions when it's awake when I come back to it. More often than not it's fine, but it's beginning to bug me. Before I went down the shop about an hour ago I put it to sleep and unplugged all USB peripherals. Came back and the thing is on, opened up Power Shell and this is what i got.

PS C:\WINDOWS\system32> powercfg -lastwake
Wake History Count - 1
Wake History [0]
  Wake Source Count - 1
  Wake Source [0]
    Type: Device
    Instance Path: PCI\VEN_1022&DEV_145F&SUBSYS_87471043&REV_00\4&c93bee2&0&0339
    Friendly Name: AMD USB 3.0 eXtensible Host Controller - 1.0 (Microsoft)
    Description: USB xHCI Compliant Host Controller
    Manufacturer: Generic USB xHCI Host Controller
PS C:\WINDOWS\system32>

How, when there's nothing plugged in to any USB port?

 

[Malevolence]

Absolutely everything was unplugged, mouse and keyboard too and any bluetooth dongles?

Yes, the only two things plugged in were the power lead to the PSU and the HDMI to the monitor. I even pulled the 3.5mm jack for the sound out too. Should I start to believe in ghosts?