Why does my screen stay active while on the phone?

[AC Question]

When on the phone, my screen will stay active. As my cheek brushes it, it tries to call the last person I spoke to or it will pick up an incoming call. Before I know it I'm talking to someone else who was calling me.

 

[B. Diddy]

Welcome to Android Central! Which phone? Check your Phone app's settings to see if there is an option to keep the screen on during a call--this option is typically found only on Samsung devices, as far as I know. If you don't have that setting, then it may be a problem with the proximity sensor. Use an app like CPU-Z to test how well the proximity sensor is functioning.