There are 2 possible outcomes for this issue:

1) If you have the same private keys for your ETH (let's name it - "A") and ETC (let's name it - "B") wallets.

Then while sending coins from another ETC (let's name it - "C") wallet you entered your ETH (A) wallet address by the mistake instead of ETC (B) wallet address, you will receive your coins to your ETC (B) wallet. As if you have the same private keys for ETH and ETC wallets it means that your wallets have the same wallet address.

2) If you have different private keys.

In this situation, you have different ETH and ETC wallet addresses. This means that you have just sent your ETH coins to the third-party ETH wallet address with the same wallet address as your ETC wallet. Unfortunately, blockchain technology doesn't allow anyone to make/change/redirect/cancel transactions, that have been already sent to the blocks. Be careful managing your funds.