u/Adventurous_Form5395

At my grandparent's house, we noticed this green wire isn't connected. It is going into the air conditioning unit and the house. Any idea what is for? We've turned the power off at the main breaker.

The air conditioner isn't working. We had it repaired last year to have the compressor replaced.

edit we got wire nuts. I was able to connect the wires. The air is cold now and I didn't die!

Thanks for everyone's help!