I don't understand what you are trying to do here. What do you mean by "put electricity AND audio through it" - ?
If you are just reducing the audio, pin 1 is ground, pin 2 goes to the amp and pin 3 is the audio input. If it's used as an input to an A/D converter, then you can hook it up to +5V like that -
- but you don't do both!
If you are reading the audio with the A/D input, take the +5V off pin 3 and replace it with just the audio signal. Use the wiper (pin 2, apparently) for the A/D input.