I think you are bang on with this..
The Answer came to me on the 20th of December. It's kind of raw and very personal.. But my Father passed away in Hospital a little over a week after the Spirit had told me to "Turn the light off".. So, Okay, Background.. When Mum died a few years ago an important gesture or ceremony for me was to open the Windows to allow her sprit to escape. I couldn't do that with Dad because he was in HDU which mean't the windows were unopenable.. So as it was a few minutes after he passed I felt the need to let him go, let him escape.. The answer came as I noticed the headlamp which had been left on since he'd arrived the day before was still turned on.. So I turned the light off.. Vwalla... That's what she meant..
This is my current interpretation to the event anyway.. There's another few hidden messages here as well that I'm still working through.. One being the importance of ceremony and gestures.. Another being intention..
Edited to add: You know, re-reading this post, the words don't seem to give the event much justice.. It was a powerful thing to light off..
I think what you intepret the meaning to be, is the most important, even if it isnt correct in the way that your guide intended it to be. Becasue as long as you take comfort in the message, and it heals or enlightens you, then the interpretation doesn't matter. you were still able to make use of or find solace in the message. In your case, the answer did indeed come to you, and from reading your story, id like to add that i think your guide wasnt giving you instructions at all, she was trying to tell you that you did exactly the right thing by turning off that light. Did you think back on this? did you wonder " i wonder if that worked, did my dad really get out? is his spirit free? since i wasnt able to open the windows?" and your guide, being the closest friend to you you'll ever have wether you know it or not, knew that this ritual of opening the window was an important one to you, and to the process of grieving and letting go. So her message was simple in it's delivery, but the implications go much farther in providing you with comfort and the knowledge that by simply turning the light on or off, you were able to continue with a tradition or ritual that means something to you, and that it worked and your father is free and happy.
and i find that when i recieve a sign, or have a dream, anything really that i know came from a higher presence then myself, if i sit around and force myself to figure it out, i get absolutely nowhere. It's when i relax, and let my thoughts flow freely, and just in general forget about it, that the meaning pops into my mind like einstein and the theory of relativity! I think that's becasue when we are thinking so hard, we dont have our subconscious open enough to allow thoughts or ideas to me implanted, but when we relax and allow them to come to us we're much more open to outside sources of information. So the answer may come from the very source that left the sign to begin with, but by thinking about it too much and too hard, we exhaust ourselves anbd block out any help we may get from our guides or loved ones. It's always for me, sometime after that i finally understand the meaning of whatever message i recieved, in some cases even years. But then in those cases i just accept that i wasnt ready for the answer, or would not believed it or couldnt handle it at the time of recieving. Trust in your insticts and gut, becasue our guides and the spirit world in general influence us in more mays then we know.
im really glad you were able to find meaning in what your guide spoke, and that it meant as much as it did to you. Her intentions were clearly to reassure and comfort you ;-) they only come to us with pure love, so there will never be a message intended to upset you.