Send BTC to xyz wallet: [H] X coin [W] BTC
This thing came new to my radar. Check this: [W] BTC [H] XMR $3,600,000 archive Read the topic.
It create doubts but seems legit too. One would consider to send the BTC to the referred wallet thinking it's a legit wallet. Trick is that the user will give you a phishing wallet site and will ask you to create a wallet in there and have the keys safe. They will then send the X coin (which they won't obviously) and once you will receive the X coin then you will be asked to give them the private key of the wallet.

Trick here is that once you will create the new wallet in the phishing site and send the coin as he instructed, possibly he will have some code injected and the BTC will immediately go to his choice of wallet. Scammers are very creative indeed.

Example victims or offers:
https://bitcointalk.org/index.php?topic=5178075.0 (offer)