I am replacing some of my old light switches. They are like decora switches, but the button is the full size of the switch plate. They are horrible. I boutgh new switches and covers to do the job a little at a time...as my house has arouns 25 of these horrible switches. Anyway...I turned the power off at the breaker box and removed the switch plates and pulled out the old switch on a double switch box. One of the switches only had 2 lines going to it...the other had 3 lines going to it. This confused me a bit, so to be safe I thought I would try to ask around and do some research. THese are not on dimmer and to the best of my knowledge, they are not 3 way switches. Any idea why one switch has 3 wires, the other only 2???