[KeepingItReal]

Originally Posted by karostay

In a 10 story building the ceiling above the 10th story has one large florescent light.
Each floor has an interior balcony
With out using any low voltage switches just 110 volts
How would you turn the light either on or off from each balcony ?

Not an engineer but I do know electricity and electronics.....

Not limited to 10 floors

How to Wire a 4 Way Switch
You may have mastered wiring a 3 way switch but do you know how to wire a 4 way switch? Well...it's not too bad...especially if you understand 3-way switches. Four-way switches are used to control power to a light from three or more different locations. You must purchase switches labeled as 4-way switches rather than 3-way or normal light switches. 4-way switches can be quickly identified by the 4 screw terminals (in addition to the green/gnd screw terminal). Two of of terminals are brass and labeled "input", the other two are black and labeled "output". It is very important to pay attention to these as shown in the 4-way switch diagram.
When wiring a 4 way switch circuit as shown below, you will use two 3-way switches and one 4-way switch. If you wanted to add a fourth switch to the circuit you would need another 4-way switch wired in the middle in the same way as the first 4-way switch. You might ask, how can I wire a 4 way switch with regular light switches, or all 3 way switches, or all 4 ways switches? The answer is you can't. You must have a 3 way (3 terminal) switch on each end of the series and then a 4-way (4 terminal) switch in the center. If you don't have the right switches you need to get the right switches rather than trying for hours to somehow make it work. I only say that because I've seen people try to figure out ways to make it work, using the wrong switches, and they end up with switches that have to be in certain positions for other switches to work and it's a huge mess to straighten out.

- See easy to follow diagram and more at: How to Wire a 4 Way Switch

More easy wiring diagrams http://www.buildmyowncabin.com/elect...-switches.html