In a properly wired switch, you should find a bare ground wire of copper. Using a DVM or voltmeter, measure the voltage between the ground wire and both wires attached to the switch. One should be hot or at 120 volts. The other wire will lead to the device the switch turns on or off. If there is no ground wire, you can run a temporary wire from a earth or pipe ground to get a measurement.
You have a 3 way switch. Your black wire is the hot wire. Your green wire is the ground wire. Your red and white wires go to the light and other switch. You should have gotten a wiring diagram with your switch.
Normally the white wire is neutral, and the black is hot. But if the power comes into the ceiling box and the light is controlled by a switch leg the white my very well be hot. If there is only one wire in the switch box that is a switch leg.
You always switch the HOT side of the light, never the neutral. This would be the black wire from your voltage source.
the black wire is the hot wire
The white wire is always identified as a neutral wire. The only time you will find the white wire "hot" is in residential home wiring. This will be the return wire from a light switch back up to the light fixture. Code specifies that this conductor has to have a coloured tape identifier to show that it is not a neutral but a current carrying "hot" conductor.
There isn't, unless you have a damaged switch.
Black is your hot wire. Red goes to the light fixture.
Run a wire from the light to the switch. At the light connect the black power wire to the black wire to the switch. Not wrap some black electric tape at each end of the white wire going to the switch (This indicates that the wire is potentially hot and not a common wire). At the switch connect the black wire to one side of the switch and the taped wire to the other side of the switch. Connect the ground (bare) wire to the green screw on the switch. Now at the light connect the taped white wire to the black wire feeding the light and connect all grounds together with a wirenut.
No it is not a standard practice. That said you will find such a connection from a light fixture junction box, that has the supply source in it, down to a a light switch junction box. The neutral for the light is already at the light junction box but the switched leg has to go down to the switch. The black "hot" wire is connected to the white wire in the cable going to the switch and from the switch it returns in the black wire in the same cable which is then connected to the light fixture.
On the "hot"wire that comes from the breaker panel the voltage should be from 115 to 120 volts. This is taken from the "hot" wire to either the neutral or the ground wire. If its not then you have a breaker problem or you are on the wrong scale of the test meter.
Look on the main fuse panel, you should find a place there.
All a switch does is separate the hot side of a voltage source from the light. This means you put the switch "in series" with the black wire going to the light fixture. The black wire from supply goes into one terminal of the switch and the black wire going to the light goes on the other terminal. The switch is grounded with the bare wire from supply and the white wires coming from supply and going to light are connected with a wirenut. The bare wire grounds are also connected with a wirenut.
Should be HOT at one side of the brake light switch
Using 14/2 or 12/2 wire, black, white and bare. Bring the hot/black wire in the light down to the switch on the black wire, through the switch and back to the light on the white wire. Connect the white wire in the power wire to the white wire in the light. Connect the white power wire from the switch to the black wire in the light. Run the black and white wires in the first light to the second light. You should wrap the white power wire from the switch with black electrical tape to cover the white so that the next person realizes it is a power wire.
If the switch is "closed" both wires should be HOT - with switch open one wire should go COLD-- if not defective switch
I believe that it is a grounding switch. If that is the case it would only have one wire going to the switch. You could run this wire to any fused constant hot. The wire would run from the hot, to the light, to the switch.
A light switch wiring is simple. You just need to contend with three wires. For typical home wiring you would have a hot wire (black), a neutral wire (white) and a ground wire (bare or green). You switch only the hot wire. The hot wire from the supply side is connected to one terminal of the switch. Connect the hot wire for the load to the other side of the switch. Connect the white wires together with a wirenut. The ground wire is connected to the ground terminal of the switch. This is often connected to the supply and load grounds via a pigtail wire and a wirenut connecting three wires together.
Red is hot Green is ground White is neutral
Bring the hot power wire into the wall switch box and run another wire out to the outlet. Tie all the whites together in the switch box under a wire nut and shove this back into the box. Tie the black incoming wire and the black wire going to the outlet together and jump a wire off this to one of the screws on the light switch. Connect the black wire going to the light to the other screw on the light switch. Connect the white/black wire to the outlet.
Remove the light sensor and place a switch between the red and black wires. The black wire is one leg of the "hot" pair and the load is connected to the red wire. This will now switch the black hot through the red wire that goes to the load.
Power out of a switch is not negative. It is still the "hot" conductor. The ground wire in a switch junction box in home wiring is the bare wire. It is nearly impossible to mix these two wires up. Most likely if the "hot" supply comes into the switch box the neutral wire will be with it. Just wire nut the two white wires together, incoming and outgoing. The two black wires will be connected to the switch to operate the light fixture.
when wiring a 3 way light switch u have to have a hot side and a switch side meaning switch one out of the two will be fed with your power 120v or 277v/ the hot wire will connect to the black screw on switch one then run 3 wires to the other switch two of those three wires will connect to the other two screws on switch one and will connect to the same two screws on switch two the third wire is ur neutral wire the white wire u have to carry over to switch two just use wire nuts for the white wire ok now the black screw on switch two will connect to the black wire feeding the light and the white wire u carried over will go to the white wire going to the light also. so you will need to run 2 wires down to switch 1 a hot and neutral/then 3 wires from switch 1 to switch 2/and then 2 wires out of switch 2 going to the light,out of the 3 wires u run from switch 1 to switch 2 the white is the only 1 that goes out to ur light together with the black wire that is connected to the black screw on switch 2 hope u can understand this try draw it out as u read it
You need to take a new wire into the outlet and to your new switch box. Black (hot) to black and white (neutral) to white Also splice the ground wire through. In the switch box you'll have your new wire from the outlet and a wire going out to the new light. Incoming black wire to one terminal on the switch and the black wire going to the light on the other terminal. The neutral wires get spliced together.
Always switch the hot conductor.
Light switch connection is usually straight forward. Find your incoming hot wires, black and white. With the switch in the off (down) position and the power disconnected , connect the black wire to the top screw of the switch. Find the load wires and connect the black to the bottom screw of the switch. Connect the two remaining white wires together with a wire nut and push them to the back of the switch box. Install the switch into the wall box, replace switch plate cover. Turn the breaker (power) back on. Flip the switch to the up position and the light should come on.