I was putting in a new air filter and noticed that there was a ground wire just hanging there. I took it to a shop to replace the spark plugs and they probably forgot to connect it back. Does anyone know where it's supposed to go? I'm thinking that bolt right above and to the right of the connector in the picture is about the right size/distance. I'm guessing they just want two different chassis ground points on the engine?

 

You seem to be a new member. Welcome to the Forum.
One thing you should do when posting questions, is identify the year and model so you can get a more accurate answer.
I can't give you a complete answer, but I took a photo of the grounds in my 2016 ES350. Hopefully it will help. My car has 2 leads from the frame ground to each cylinder head in my 3.5 V6.