What is wrong with my 2005 Honda Civic?

The engine won't turn over, or even click. When the ignition is turned the odometer starts flashing, and the orange dials on the gauges start jumping erratically. This also happens when we try to turn on head lights or other electrical switches. it does this with no key in ignition also, and keeps going for several minutes after the key is removed. The guy at the auto parts store said it might be the Body Control Module. Any ideas?????