How to contact an ethereum address?

I have sent some ether to an incorrect address, what is the best way to contact the owner of that ethereum address? Is it possible? I want to reach out to the owner if he/she can send it back to me.

I have tried etherscan but the owner of that address seems to be offline. I am also planning to use ethermail.io to see if I can contact the owner. Are there other ways?