Some Gold Tidbits and Where to Find Them,

That part in the mouse. It can be broken down a bit furthur. Its a image sensor and looks quite pretty. It has Gold wires on it, just like a LED, but about 6 or 8 of them.
Actually image sensors are great Gold wires sources.
Those camera ones, Office photocopy machines have a larger rectangle one, also very nice looking.
And computer flatbed scanners have a long strip one with over 250 Gold wires in it.



Other places I look are contacts on relays, the little block on the boards, normally blue or black.
Switches, the ones in microwave doors ( mostly Copper/Silver or Silver) and the same switches from dishwashers tend to be Gold ir Gold plated.

The little switches from behind tapedeck units for switching the FF and Rwd motors on and off. Simikar switches from other places.

Any switches from high quality electronics. The little block ones with a bunch of switchs on it are great too.
Mostly the Gold wires are exposed so I keep the strip in its black plastic casing support bar.