Hello everyone,
I searched the forum and found a few other posts asking about wall smears that answered my other questions (the auto-populated "related topics" is a great feature!) but have another one.
On my wall, right next to a pedestal oscillating fan, I found a black line (almost like the shape of an ant). I touched it with my dry finger and it smeared, there was definitely a scent to the stuff that was on my finger (not necessarily "bad" but something was there), and when I wiped it again, it literally disappeared. You cannot tell anything was ever there in the first place. It felt a bit like oil (maybe got flung off the fan motor?), but I wanted to check with you guys -- would a BB fecal spot a) wipe easily with dry finger and b) disappear after second wipe (white wall).
Background info - I haven't had bed bugs here (live here for years) and no other signs like bites or anything on my mattress/sheets. Spot was at knee height a few feet from bed, next to pedestal fan.