At this point you need to make sure the wire is neutral. In a standard switch or dimmer the hot wire is using one of the 2 wires connected to the switch.

Diy How To Use A Multimeter To Test For Hot And Or Neutral Wire When Doing Electrical Work
How to check neutral wire. If you see a. Buy romex 6 wire meaning each hot wire and the neutral wire are six gauge. On the house wiring side neutral will be black or sometimes blue. The supply to the breaker board will typically be split single phase meaning two hot wires serve the breaker board along with a single neutral connection and a single ground connection. Strip off about 12 inch 13 cm from the end of each wire on the base. The hot wire is normally black.
Theres a good chance your existing switch does not have neutral in which case youll have to run neutral from an. If you cant find the source of a problem. Common house wiring colors color is usually the best way to identify electrical wiring. All wiring looks the same on the inside but the outside coverings come in different colors. Then push the wires on the base into the live and neutral ports of an outlet. Disconnect the breaker panel which will serve the new 50 amp outlet by shutting off the main breaker.
On an outlet or fixture thats on the end of the run the neutral wire sends the current back to the source. Screw a 100 watt bulb into a base socket with 2 wires attached to it. The hot wire has no ribbing or stripe or it may be coated with black or red insulation. When you open an outlet it can be useful to figure out the position of the outlet or switch in the circuit as well as the function of each wire. This knowledge can help you pinpoint problems and connect wires to the correct terminals when making repairs. In polarized appliance cords the neutral wire is identified by a white stripe ribbing or white insulation.
The standard color for your hot wire is black. If the person who installed the wiring followed regulations the house wiring colors should give away the identity of the hot and neutral wires. Locate an unused double pole 50 amp breaker or install a double pole 50 amp breaker in a vacant location. The only way to do this is by checking the voltage 110v120v between the white wire and the hot wire in the box. You can use a lightbulb to check earthing in a socket.