Does the code specify somewhere that single pole light switches must be labled on and off and installed in the orientation so that on is up? One of my NEC class instructors had a good story about the honney well plant that he works as the head electrician. Says an inspector flagged the campus for having three way switches that are not labled on and off hah. As a joke and to suit this misinformed inspectors requests he had a solution. Next to the light switches in a portion of the building he printed a sign and mounted it next to each one. "When the switch at the end of the hallway is up and this one is down, light is on. When the switch at the end of the hallay is down and this one is down, light is off........................." But is there any code as to snap switches orientation for lighting loads. Know it would matter if it serves as a disconect but what about lights?

Ok here is my wiring One 4-way switch Top lft Black screw Red wire. Top right black screw Black wire Bottom left, Silver screw Red wire, bottom right, silver screw, black wire 3-way switch. Top left Silver screw, black wire, top right silver screw-red wire. Bottom left Black screw white wire. Out of the box for the dimmer switch. One green, one black and two reds. Now I need to figure out which are the travlers and which is the hot. Thanks

I would start by extending the four switches from their junction boxes to see if anything 'looks wrong'. 'Very old' installations can accumulate insulation, debris, corrosion, etc that can provide a high resistance path for limited current to flow through, especially if it gets damp. Corrosion can be internal to the switch(es) so replacement, as mentioned by Greg, is something I'd plan on. BTW, if you are not familiar with four switch hook-ups, you'll need two three-way and two four-way switches.

I didn't really read the subject line. Here's another interpretation: If you are trying to control 2 lights (both going on/off at the same time) from 4 different places, then you don't just use 3-way switches. You need 4 way switches too. I think it needs two 3-ways and two 4-ways. I'm sure you can google it to get a proper wiring diagram.