Spitballing here.
My guess is the physical pack of smokes is functioning as a soothing/comforting totem. I came from cigars; I was soothed by their beauty, craftmanship, feel, etc. I keep an old dark brown eVod Mega around because it is the size, shape, and color of the Churchill-sized cigars I preferred. Fits in the hand just like a cigar.
Our minds try to protect us with defense mechanisms, and sometimes old defenses are no longer helpful. They are also good at hiding.

Here are some questions that might help flush out the trigger(s):
What would happen if you wrote on the pack with a marker? Or blacked out the logo? Or blacked out the whole thing?
What would happen if an empty pack were resealed and left in the normal place? What if it were filled with something before resealing so that it weighed the same as a full pack?
What would happen if you placed a small rectangular
mod inside an empty pack of smokes?
What would happen if you placed a pack-sized object in the spot you usually keep the pack of smokes?
What if the pack was still there but placed in a paper bag or in a dishtowel?
What would happen if you didn't own a lighter?
What would happen if you "field stripped" (removed the
tobacco from) a cigarette to smell from time to time?
What if you opened a new pack and dribbled some vinegar into it and let it dry out?
What if you put something sticky on the pack, like a thin layer of grape jelly?