in replacing a ugly old light switch, i see that inside the box, the white wire is connected through from top/bottom, and the switch has 2 blacks and a red, no ground. This switch controls an outdoor motion sensor floodlight. I have attached a picture. This is the only switch that controls the light.
Can I just put another 3-way switch in, wire the same way, and ignore that fact that I do not need a 3way?