Continuously cranks

So my uncle and I first came across this issue as a no crank situation and we’ve so far replaced the battery, the connections to the battery, the ignition switch. Now we replaced the starter and the solenoid by doing so we unhooked the battery and when we hooked it back up it began to crank, even without the key in the ignition. Afterwards we checked the ignition cylinder and it looked fine. Next we got a different, and new, starter/solenoid and same issue has occurred.