Accidentally sent THETA or TFUEL to an Ethereum address
Your THETA/TFUEL tokens actually went to the equivalent address on Theta blockchain. Since Theta and Ethereum blockchains use the same cryptography they have the same address format, so every Ethereum address is also a valid Theta address and vice versa.
To access your tokens, you'll need to import that Ethereum address into the Theta web wallet with the private key of that address.
1. Take that Ethereum private key and enter it in the Theta web wallet here: https://wallet.thetatoken.org/unlock/private-key
2. Make up a one-time temporary session password (doesn't matter what this is) and unlock the wallet
3. You should now see your mainnet Theta tokens, and the address displayed in upper right hand corner should be the same as your Ethereum address
If you only have a seed phrase, not a private key, you'll need to derive the private key from the seed phrase first. This adds a few extra steps to the process, but if you follow these instructions it should only take a couple minutes. We recommend going offline for the portions where you are deriving your private key and entering it in the web wallet, so that your private info isn't exposed online.
2. In the field "BIP39 Mnemonic" enter your seed phrase
3. For the "Coin" field, select Ethereum
4. Go down to where is says "Derivation Path" and select BIP32
5. In the "BIP32 Derivation Path" field copy and paste m/44'/60'/0'
6. If it all worked right, when you scroll down to the "Derived Addresses" section you should see the first address listed is your Ethereum address and it will have a corresponding private key. Take that private key and go to step 1 in the first set of instructions above.