hi!
So, I am making a map, so, I have added a Power Switch, but I want to know if I can turn the lights on when I activate the power switch...

Thanks for help

Yes this is totally possible. Your lights need to be real lights. Not just adding a light to your map (if you just add a light and leave it you notice that no shadows are added when rendered). This can be done by setting the light to PRIMARY_OMNI or PRIMARY_SPOT and setting it up with an info_null (right click menu) and selecting the light first then the info_null and hitting w. Then while just selectiing the light hit n and do this for the kvps:

targetname:light_electric
intensity:0.001
script_float:1

Script float is what it will change to once the power is activated and intensity is what it will be before.
Be sure to set up the light properly with PRIMARY_OMNI or PRIMARY_SPOT and the info_null and don't make the fov_outer bigger than 120 or else it won't render it right and keep the fov_inner lower or the same as the fov_outer.
Also as a side note lighting may be weird before you put in your script_brushes (if using those for your doors) not really an official thing but i noticed that when messing around with lighting.

Yes this is totally possible. Your lights need to be real lights. Not just adding a light to your map (if you just add a light and leave it you notice that no shadows are added when rendered). This can be done by setting the light to PRIMARY_OMNI or PRIMARY_SPOT and setting it up with an info_null (right click menu) and selecting the light first then the info_null and hitting w. Then while just selectiing the light hit n and do this for the kvps:

targetname:light_electric
intensity:0.001
script_float:1

Script float is what it will change to once the power is activated and intensity is what it will be before.
Be sure to set up the light properly with PRIMARY_OMNI or PRIMARY_SPOT and the info_null and don't make the fov_outer bigger than 120 or else it won't render it right and keep the fov_inner lower or the same as the fov_outer.
Also as a side note lighting may be weird before you put in your script_brushes (if using those for your doors) not really an official thing but i noticed that when messing around with lighting.

i tried that it didnt work