Head lights turns on 2hours after ignition is off 2005 Gmc envoy 4.2 l6

Wilbert, there is a re-call for this issue. You can bring it in OR just replace the low beam headlight solid state relay # 46. Always keep an spare in the glovebox, it's that common of a problem. As far as the recall, there is a permanent fix finally, but they're just replacing the relay. With my experience even the new relays will go out at some point. In a pinch, you can swap #46 with the one right next to it, (fan clutch), will get you light in a pinch but watch your temp.

The headlamp driver module (HDM) is an electronic module that provides electrical power to the vehicle low beam headlamps. The HDM is controlled by a pulse width modulated (PWM) ground signal from the body control module (BCM). The BCM determines the desired lamp intensity using the ambient light sensor, multifunction switch and the park brake switch as inputs. In general, the HDM will operate in 1 of 3 modes:
Your best bet have it checked by a qualified repair shop ! May have DTC'S diagnostic trouble codes .
DTC B2575
DTC B2575 Headlamp Control Circuit
When the body control module (BCM) senses a request for headlamp or daytime running lamp (DRL) illumination, the BCM sends a pulse width modulated (PWM) ground signal to the low beam headlamp driver module through the low beam headlamp driver module control circuit. The low beam headlamp driver module will illuminate the headlamps, adjusting the intensity based on the PWM signal received.
DTC B2580 Headlamp High Beam Control Circuit
DTC B2645 Ambient Light Sensor Circuit
The body control module (BCM) monitors the ambient light sensor signal circuit in order to determine if the daytime running lights (DRL) or the auto headlights (ALC) should be turned ON in the AUTO mode. When the BCM senses the ambient light sensor signal voltage is between 1.75-4.9 volts, either the DRL will be commanded ON or the ALC will be commanded ON depending upon the amount of light received by the sensor.