1. Everything there is to know about the fan.
2. Everything there is to know about the 555 timer project.
3. Everything there is to know about the lamp dimming project.
4. What it is that you are trying to do.
A temperature control for gpu and cpu fan and can include PWM current control for fan speed. PWM is related.
First is a temperature sensor circuit. A micro controller may or may not be the method.
by searching various key words you can find them Fan Temperature Controller Module,DC 12V 24V 48V 4-Wire PWM Driver Module for PC Fan/Alarm
Short answer is YES! Now to discover what it is that you want it to do.
It seems that the fan is used to control a temperature, probably by changing the cooling air flow. And the light dimmer can be used to control the heating provided by the light. Those are my guesses.