You have a balance in an old Ethereum contract (The DAO, EtherDelta, IDEX, the 2017 ENS registrar, DigixDAO and others). Each contract has its own withdraw call. Use the wallet that owns the position.
- The DAO: on the DAO token 0xbb9bc244d798123fde783fcc1c72d3bb8c189413 call approve(0xbf4ed7b27f1d666546e30d74d50d173d20bca754, yourBalance). Then call withdraw() on the WithdrawDAO contract 0xbf4ed7b27f1d666546e30d74d50d173d20bca754. It pays 1 ETH per 100 DAO.
- EtherDelta 0x8d12a197cb00d4747a1fe03395095ce2a5cc6819: from the wallet that deposited, call withdraw(amount) for ETH or withdrawToken(token, amount) for a token. Amounts are in the token's smallest unit.
- IDEX v1 0x2a0c0dbecc7e4d658f48e01e3fa353f44050c208: call withdraw(token, amount). Use token 0x0000000000000000000000000000000000000000 for ETH. It reverts if your last IDEX activity was fewer than 240 blocks ago.
- 2017 ENS registrar 0x6090a6e47849629b7245dfa1ca21d94cd15878ef: call releaseDeed(labelhash) for the name. The labelhash is keccak256 of the name without .eth. The deposit goes back to the deed owner.
- Other contracts (DigixDAO, Neufund and more): use the contract's own withdraw or refund function on Etherscan from the owner wallet. Check the contract's code first.