The reply I received from the OC claims they have legal advice supporting their position. How can I dispute this? I suspect that getting a lawyer might cost more than just paying for the rewiring.
Legal advice from whom? The strata manager? The bloke at the chip shop? As a member of the owners corp you are entitled to see all correspondence to and from the OC and the committee, so ask them to send you a copy of the “legal advice”. If it’s from anyone less qualified than an experienced strata lawyer, then you can file it in the “highly dubious” basket.