fan in the front of my house in the attic
I don't know why I missed this a couple of days ago, so sorry about the delay.
It is probably a gable ventilator fan.
It probably has a thermostat which will turn the unit on when it reaches the temperature setting that was done before you were aware of it.
If it does not run at all, then it is probably a burned out motor or a short in the wiring, or there is a switch which needs to be turned on to supply the juice to it.
Pictures would be helpful if this does not directly answer you question.