We claimed the second stimulus when we filed our federal taxes. Found out today the money was deposited into another account. Do we file amendment or call IRS?

DO NOT file an amended tax return with the IRS. If you entered an amount but made a mistake in calculating the amount, the IRS will calculate the correct amount of the Recovery Rebate Credit, make the correction to your tax return and continue processing your return. If a correction is needed, there may be a slight delay in processing your return and the IRS will send you a notice explaining any change made.

To check the status of your refund from your original return, check Where's My Refund?

Thank you very much.  I was so paranoid they'd think we committed fraud or something.  So I can just wait to receive notice from them and don't need to contact them first? 

Yes, that's correct. You don't need to do anything about that, just wait for the letter form them.