If you have access to the private seed of the Bitcoin Wallet that received the Litecoin, you can generate all the addresses and private keys here https://iancoleman.io/bip39/

You'll basically enter the private 12-24 word seed there and set the coin to Bitcoin.

Then scroll down and look for the address that received the LTC. Reveal the private key on the right and you can then import the funds that are stuck on the BTC Wallet address back into a Litecoin wallet by scanning the private key bar code or entering the private key text into a wallet that supports importing of private keys.

Something like Edge Wallet would work or any non-custodial wallet where you can import private keys would work as well.

After doing that, it's probably wise to make a completely new wallet as the Bitcoin wallet has had the private seed exposed by entering it.