Hi Eonn,

Computer Techs and Electronics Techs (of which I am both by profession), do indeed connect their ESD wrist bands and ESD mats to a variety of different earthing sources (there are many options available). You definitely cant just connect it to a random metal object, as it wont work unless that object is earthed.

Using the metal case of a computer will work, but only because the metal case of a computer is connected to the mains earth pin (must be law in most countries). This does make a handy earth source when working on computers. I have often earthed myself via the case of a computer, especially when replacing sensitive components in the computer. Clipping an ESD wrist band to the case of a computer is fairly safe despite it using the mains electrical earth. ESD wrist bands have a built in resistor that protects the wearer in the event of a mains electrical fault (extremely rare event that pretty much never happens).

Given the lack of other options for your room, it looks like you best approach would be the metal case of a computer, or a store purchased professional mains earth bonding plug (see images in previous postings on this thread).

The only other option that I can think of is a wall mounted radiator. If you have a wall mounted radiator for heating, they are almost always earthed.

Best Wishes

Jexx