Is this a scam?

[dmb2023]

I just received money from someone I don't know.  They claimed it was sent by mistake stating my email is one letter off from the intended recipient.  Now they are asking for a refund.  How do I know if this is not a scam?

[kernowlass]

@dmb2023 

How can it be a scam, they aren't asking you for funds?

If the funds are SHOWING as cleared and not pending or on hold in your paypal account then you can click on the transaction and then click on the refund option bottom of that details page. 

HOWEVER if its on hold then state you will refund when the funds clear.

ALSO if you were charged a fee (will show on that details page) then you don't get the fee back when you refund. So tell the sender as it was their fault you will part-refund minus the fee element so you are not out of pocket.