So I got my income tax check back in April and this past Friday I ended up getting another check in the mail for 1992 why would I get a second income tax check

You will get a letter in the mail in a week or two explaining the reason for the additional tax refund from the IRS.

Or you can call the IRS to inquire -

Call the IRS: 1-800-829-1040 hours 7 AM - 7 PM local time Monday-Friday
When calling the IRS do NOT choose the first option re: "Refund", or it will send you to an automated phone line.
So after first choosing your language, then do NOT choose Option 1 (refund info). Choose option 2 for "personal income tax" instead.
Then press 1 for "form, tax history, or payment".
Then press 3 "for all other questions."
Then press 2 "for all other questions."
- When it asks you to enter your SSN or EIN to access your account information, don't enter anything.
- After it asks twice, you will get another menu.

Press 2 for personal or individual tax questions.
Then press 3 for all other inquiries
It should then transfer you to an agent.