In the US a modern 120V circuit will have a ground. Anything plugged in will be grounded (if it has a ground pin on the plug).
If you have a metallic zipstrip/surge suppressor, you could ground to it's metal case using an existing screw or carefully
install a self tapping screw.
Your computer will also be grounded and will have a few screws that would be easy to attach a ground wire to.
Is there any way to check whether metal attached to the ground or not?
A voltage tester will read 120 volts from hot to anything grounded.