No it's not normal, at least not for the effect you're intending.
Here's the problem:
SetEntityPlayerInteractCallback("lever_nice01_1", "LightsFunction", false);
You're using SetEntityPlayerInteractCallback which means it will trigger instantly whenever the player interacts with it, for example simply touching it.
Use this instead:
SetEntityConnectionStateChangeCallback("lever_nice01_1", "LightsFunction");
Take a look here for a tutorial on a similar matter:
http://wiki.frictionalgames.com/hpl2/tut...cretshelfs