Runs continuously until we flip the breaker

Once every month or so, sometimes longer, our Nest Thermostat will run continuously until we go down in the basement and flip the breaker. Turning the unit off does not work, it keeps running.

For example, last night I woke up in the middle of the night sweating because the heat was up to 79 but we had it set at 69.

Is this a problem with the Nest’s connection to our HVAC or do we need to call an electrician?