Ok so I have Mojave up and running and everything working except my USB dongle with Realtek 8188EUS chipset. ioreg shows the device:
ioreg -p IOUSB
+-o Root <class IORegistryEntry, id 0x100000100, retain 10>
+-o AppleUSBEHCI Root Hub Simulation@1a000000 <class AppleUSBRootHubDevice, $
| +-o IOUSBHostDevice@1a100000 <class AppleUSBDevice, id 0x1000002c9, regist$
+-o AppleUSBEHCI Root Hub Simulation@1d000000 <class AppleUSBRootHubDevice, $
| +-o IOUSBHostDevice@1d100000 <class...
Realtek 8188EUS USB Dongle
ioreg -p IOUSB
+-o Root <class IORegistryEntry, id 0x100000100, retain 10>
+-o AppleUSBEHCI Root Hub Simulation@1a000000 <class AppleUSBRootHubDevice, $
| +-o IOUSBHostDevice@1a100000 <class AppleUSBDevice, id 0x1000002c9, regist$
+-o AppleUSBEHCI Root Hub Simulation@1d000000 <class AppleUSBRootHubDevice, $
| +-o IOUSBHostDevice@1d100000 <class...
Realtek 8188EUS USB Dongle