I came home last night and the house was up to 75 degrees when the thermostat was set at 67 degrees and the furnace was still running.when I move the thermostat I can hear it click at the temperature the room is at.I have to shut it off with the breaker

There are several possibilities:
To eliminate the thermostat, take it off the wall & disconnect the wires. Pay attention to which wire goes to which terminal.

If that doesn't work, disconnect the thermostat wires from the furnace.

If the furnace still wants to run, you likely have a bad control board.