I'm trying to install a Leviton #6674 slide dimmer with switch replacing a standard switch. After I pulled the switch plate off I found that there is 1 black, 1 white and 1 red to the old switch as in the picture. And that is all that is in the wall box. Not what I was expecting, but the house was built in 1965. This is the only switch to the light as far as I know. On the new switch I have the green ground, red, and another red labeled as the 3 way switch wire and a black wire. Will installing this be possible without changing a lot of wiring? How would I go about wiring this? Thanks for any help on this!