You can either think about this way:
Someone was hiding in a wardrobe and you found them. Here "hinding in a wardrobe" is used to emphasize our disbelief that this particular person was hiding in such obvious place and it took us so long (or so little) to find them.
Or
You are hiding in a wardrobe and have found them. Here "hiding in a wardrobe" is used to define what you were doing when suddenly you found that person. For example, you play hide&seek, your friend hasn't gone out of their spot since a while. You jump in your wardrobe, then you realize you're not alone and you say "Hiding in a wardrobe, I have finally found!" (cause you hid in a wardrobe and found them by accident)
These are two different meanings and I wonder... Are both of them correct and this sentence can be interpreted both ways?