Vocative comma or comma splice?

Question

If I wanted to start a sentence with "hey" and follow that with someone's name, would a comma go after the name too? Here's what I mean:

1:

"Hey, Thomas, I'm staying home today."

2:

"Hey, Thomas. I'm staying home today."

Is it wrong to have the comma after Thomas?

Answer 1

Yes, put a comma both before and after the name.

I was taught this little trick: if you remove the word between the commas ("Hey, I'm staying home today.") and it's still a complete sentence, then the 2-comma rule applies.