Hoping someone might know the reason behind this. I just purchased as a lot off Ebay ten (10) "Battlestar Galactica" (Topps 1978) unopened packs and every single one of them contained a "Star Wars" (Topps 1978) series V sticker !!
Was this not uncommon back-in-the-day ? I've opened packs where there were no stickers, or even 2 stickers, but never stickers from a different set before.
Opinions ? Thanks !!
Are you sure the packs were unopened?
There are strange things that happen every so often. In baseball there are cards with 1979 fronts and 1978 backs (not sure if these were sold in packs or cut from a scrap sheet).
I also recall there were some 1978 Baseball (?) cards with Mork & Minday stickers on back.
So strange stuff can happen.
But personally I'd still go with re-sealed pack as the most likely explanation.