I have a ceramic glass cook-top electric range with built-in microwave drawer. I'm having an issue with the right front burner not turning off when the knob is in the off position (The right front burner also has small and large cook areas controlled by the same knob). The first time this happened I noticed the hot surface indicator remained on longer than normal and it felt like the burner was putting off heat (although no red glow was seen). I unplugged the range, waited about 15 seconds and plugged back in. I then turned on the burner - large cook area. I saw a red light flash (kind of like when a light bulb burns out) in the center of the cook top (not where a burner is), then the right front burner turned on (glowing red). When I turn the knob to off the on/off indicator light went off but the burner remained on and glowing. I can unplug the range and repeat this process. The other burners appear to work normally as does using only the small cook area on the right front burner.

My questions are:
1.) what's causing this problem and how to fix?
2.) if I don't use the right front burner will it be safe to leave the range plugged in and use the remaining burners, oven, and microwave?

Thanks
Jon