You need to check both sides of the terminals in the fuse box for fuse four to be certain you have voltage. If you didn't check the supply side of the fuse, you'll always show no volts. You should have 2 male spade connectors on the brake switch. Green and green/purple. Since you've got 12 v on the green wire at the brake switch you probably have no problem with the fuse box. On the brake switch connect the hot green wire to the green/purple wire with a jumper, and you should have brake lights, and either a bad or misadjusted brake switch. The brass fitting on the switch you mention is just the mounting threads for the switch. The pastic plunger on the end of the switch is responsible for making the connection in side the switch. There should be no metal contact to the brass switch threads from the brake pedal lever. From what you've described so far, I think you have a bad switch. Jim