In my house, certain switches are used many times per day while others are seldom used. We might be amazed if the switch had a use counter to display the number of times it has been cycled. If it is any consolation, today's cheapest switch probably has an operating life exceeding that of the finest switches of the 1930s and 1940s.

I'll be honest I didn't read your entire post, but the solution is simple. It sounds like you only have three conductors and a ground in the box you replaced. In this case the electrician sent the hot back to that switch box through one of the conductors in that single wire. Most likely the white or neutral wire. Try putting the white wire onto the common screw and see if that fixes it. Make sure you turn off the breaker first and test all of the conductors for power before sticking your hands all over them. A sure fire method to find out which conductor has been dedicated as a hot or common wire, would be to dismantle the first switch and see which wires are jointed together with the hots in that box. (I.e. if you see two or three black wires wire nutted together with a white wire, then that's the designated hot.) Your original electrician most likely pulled the conductor to the light from the wrong side of the circuit. To answer your question if it is dangerous....I wouldn't say it's "safe" to leave it how it is, but I have been on service calls a thousand times where the customer claims their three ways operated incorrectly for years without incident. If it's an older dwelling, the hots and joints may be made up in the box the light hangs from, in this case the solution will be the same. The only difference is you wont be able to see what wire is designated to send the hot back to the right side of the circuit by looking in the other switch box.. I would advise you to have an electrician rewire the switches eventually. Those neutrals are designated as neutrals to balance the load on the circuit. Designating one as a conductor is common practice, but imo is lazy and incorrect.

What do things look like in the other switch box in the closet you are talking about? Harder to see is what wires enter and exit the box at the light. The simplest set-up for a home owner to deal with will have a single gang box with one non-dimming 3-way switch at each location, and just one (black/white/bare ground) cable and one (black/red/white/bare ground) cable in the box with the switch. The cable that contains the red should go from box to box and makes up the travelers. The black and red ends of this cable should land on the screws on the switch that are the same color as each other (usually not black). The other cable either comes from the panel (the feed in) or goes to the light (the feed out). Put the black from this cable under the unique colored screw (usually black and sometimes called the common or point). Splice together all of the white wires and use the bare ground to ground each other and the switch and the box if it's metal. If you have a different wire arrangement than this, (and there are several that are both different and correct), and if you have only a small amount of experience then you would probably be well served by hiring a pro. I personally can't recall ever seeing or installing a 3-way in a walk-in closet and the black conductor landed on the ground screw makes me think that you will end up hiring someone to sort this out. Good luck.

Hi Greg, Could I bug you one more time? Old fan: 3 wires - black for fan motor, red for light, white neutral New fan: 2 wires: black for motor, white for neutral I've got three wires at the ceiling...black (always hot), red (controlled by switches), and white. If I hook up fan unit to black and white, switches are now wall ornaments. If I hook up to red and white, I can shut off power to the unit. So, I will be not using one wire at the box. Am I understanding this correctly? The documentation/manual with the fan assumes hot and neutral at the box. Thanks! :)