N800, 000 Credit Alert From An Unknown Person – What Will You Do?

I came across this interesting story online and though I don’t know how true it is, I decided to share it. 

Read the story below and let’s know what you will do if you were this guy:

“It sounds silly but believe me it is real. I received credit alert about a week ago notifying me of N800, 000 into my bank account from an unknown person, I was extremely surprised I even thought it was  N800 until I wiped my eyes in disbelief and looked again and it was still there.

I quickly logged into my mobile money app to see my balance and the money was actually there. I called all the people I knew to find out if anyone had sent me money but none of them did, though I didn't tell them about the N800, 000 I asked tactically and up till now nobody knows about the money. 

Please advise me before you people hear stories that touch. 
Should I go and withdraw the money? 
Should I wait like months or even a year? 
If it happens to be the bank’s  mistake, will they hold me responsible after I have spent the money? 
Please advise me on what to do.” 

If you were in his shoes, what will you do? Spend it or alert the bank about it? Let’s talk!