How can I legally break my rental lease?

The electrical issue could be your ticket out of the lease if the landlord refuses to fix it, but you will need to have it inspected at your own expense to determine if it is a fire hazard. Other than that I suggest you look for your way out in the lease you signed and then look up your state's landlord tenant act. Laws vary from state to state. Typically a landlord is required to serve the tenant a 3-5 quit notice before the landlord can file for an eviction. Serving a quit notice (aka a pay or quit notice) is not seen as the landlord breaking the lease because it is not served unless the tenant is already in breach of contract (typically for not paying the agreed upon rent in a timely manner). You may have to chalk this one up to experience and take the time to fully inspect any property you move into in the future. Good Luck.