And strangely I don't feel like I participated in anything regarding NFT on the TON network but I see some NFTs in my TON wallet. I don't know if this is some kind of free airdrop? but for sure if you find something suspicious then you should avoid it.
in this case, I personally will ignore the NFT for the sake of wallet security. I try to avoid tokens, or NFTs that suddenly appear in our personal wallet, especially since the wallet has never been used for any event.