The Force exists in all living things. Most definitely capable of holding light or dark side affinity.
Droids have a defined intelligence but no soul and life energy. The imperial probe droid’s association to an “evil faction” is what aligns it as a dark side character. The same could NOT be said for innocent imperial citizens however, that do not act on national directives or a product of the empire, merely an asset or notable collateral that doesn’t sway one way or the other.
Just my 2 cents on the early posts about wampa’s light/dark identification.
*another possibility is that this is the SPECIFIC Wampa that attacked Luke - not a nameless toon that mascots the species. That individual Wampa could have been particularly closer to the dark side based on location and the presence of galactic conflict (or force-sensitive hotspots from Hoth itself). It’s possible that other wampas could have been good-hearted and nurturing in spirit. The Force is a complicated web.