I'm trying to wire a basic toggle switch off of a 4-wire cable with no ground. It's for a furnace shutoff switch, and I'm running into this problem because I recently just removed a few basement lights that were on the same circuit, and now I can't get it back together working again.
A nearby junction box looks like this: http://yfrog.com/jmphoto1fdnj
So, there is a white wire and an orange wire on the left that goes to the switch, and is fed by the 4-wire cable on the right, which has a black, a white, and 2 orange wires. One of the orange wires from this power feed passes straight through to the switch (no wing nut originally), while the black/white/other orange of the power feed cable were wingnutted/spliced to some basement lights that I removed this morning.
And just for clarity's sake, this is the furnace disconnect switch, with white/orange wires coming from the left side of the junction box: http://yfrog.com/15photo2pwj
My Sperry ET6102 voltage tester shows a nice bright light when I probe from the black of the power feed to the white of the power feed, and also when I probe the spliced orange of the power feed to the white of the power feed.
I get a very dim but noticeable response when I probe from the black of the power feed to the white from the switch, and similarly from the spliced orange of the power feed to the white from the switch.
FYI, it's a 1960 house with no grounding anywhere, if that helps.
How can I properly reconnect that furnace switch?