As far as I know, you cannot fake a "wallet.dat" file. The closest thing one can (probably) do is running a Bitcoin network from zero on a local network of offline PCs and mining it using them, basically simulating the creation of BTC. (edit: seems like I was wrong, read reply below)
Anyway, besides using this for educational reasons I don't think your question serves any purpose besides trying to find a way to scam others. No, Bitcoin cannot be faked.
you are not aware of many things if you don't know that bitcoin wallet can be facked,
read ETFbitcoin reply
and you will have your answer
and if i have to find a way to scam other then i am not posting this question here, i am only creating awarness