Why is there no voltage going to the switch?
The problem is whatever is feeding the switch. That’s going to be tough to trace without the electrical plans showing how things were wired. One of the switch wires is connected only to the bulb. If there is no bulb then that switch terminal isn’t connected to anything – there would be nowhere for any voltage to come from.
What’s the voltage in the ceiling with the switch off?
With the switch OFF, there was 80V across the switch terminals. 0V with it ON (as it should be). Weirder still is that there was 80V from the top terminal to ground, but 20V from the bottom terminal to ground (with switch OFF). Is this just because of the open connections dangling in the ceiling?
What happens when you close a 120 V switch?
When you close the switch there would be close to zero volts ACROSS the switch. There are problems with this measurement. The 120 V that you measure might not be able to carry an appreciable current. The switch when attached to a load has a very small voltage drop. The contact resistance could be 0.010 ohms.
What do you mean by neutral going to switch?
Neutral is close in voltage to ground as they connect in your house, usually in the main breaker box. 1: Hot incoming power. I see 3 wires twisted, so power in, power out, and power to switch. 2: Hot wire to your switch. Note wirees 1 and 2 should always have power. 3: Switched hot wire. This is the wire that goes up to your light fixture.
The problem is whatever is feeding the switch. That’s going to be tough to trace without the electrical plans showing how things were wired. One of the switch wires is connected only to the bulb. If there is no bulb then that switch terminal isn’t connected to anything – there would be nowhere for any voltage to come from.
What’s the voltage in the ceiling when the switch is off?
In your description you say you have 60 V in the ceiling box with the switch off and 120 V with it on. Power has to be fed either to the ceiling box or the switch box.
When you close the switch there would be close to zero volts ACROSS the switch. There are problems with this measurement. The 120 V that you measure might not be able to carry an appreciable current. The switch when attached to a load has a very small voltage drop. The contact resistance could be 0.010 ohms.
Neutral is close in voltage to ground as they connect in your house, usually in the main breaker box. 1: Hot incoming power. I see 3 wires twisted, so power in, power out, and power to switch. 2: Hot wire to your switch. Note wirees 1 and 2 should always have power. 3: Switched hot wire. This is the wire that goes up to your light fixture.