@eli_singer The barrel plug of the power supply measures 5.4 mm to 5.5 mm outside sleeve (-ve contact) on my device, and the Switch's inlet socket measures 6.2 mm for the barrel diameter (for clearance).
The inside pin receptacle of the power supply plug is a smidgen under 2.5 mm diameter, while the pin (+ve) of the Switch's 9 V inlet socket appears to a about 2.0 mm as near as I can measure without cutting it open (not gonna do that!).
I have a DC plug pack from an electronics store that has multiple tips. Three of them have the right barrel sleeve size. Two of those have a pin receptacle too small or too loose (loose can cause heating). There was a Goldilocks one that was just right. If wiring your own then make sure to connect the positive to the internal pin and the negative to the outside sleeve or you'll damage the switch. Also make sure the supplied voltage is 9 V dc and at least 0.6 A or more (or 600 mA or more, same thing).
CAUTION: Most USB hubs will only supply 5.0 V which is NOT ENOUGH to drive this switch, except if the hub is USB PD it can deliver higher voltages BUT has to have a compatible downstream device to negotiate with so it can deliver 9 V @ 0.6 A or it just won't do it. So, I don't think you're going to be able to do what you want. Sorry.
Maybe this'll help understand the measurements (actual photo of my switch and plug):