For cosmetic reasons, I've been replacing the switches and outlets in my house (from beige to white). It's been going well until I ran into two 3-way switches in a hallway that turn off and on one hallway light. I first replaced one switch with a single pole switch, turned back on the breaker to test and the hallway light stayed on and wouldnt turn off. Then realized it was a 3-way, went to the store and picked up 2 3-way switches and proceeded to switch out the wrong single pole switch (both switches have a red, white, black & bare copper wire)- however I'm certain I don't remember what was the common or travelers. Consider this switch #1. To further my stupidity, I thought I'd switch the other 3-way out (switch #2) (so they'd match) and when I turned the breaker back on I heard a buzzing noise and the breaker clicked off (3/4 position to the on switch). I removed both switches, was very careful that no wires were touching each other and turned the breaker back on- still buzzed and switched off. I've since tries a couple of combinations with no success. Any suggestions on what combination to use?