Decor and furniture
Sign Canvas Wood 3x2
It's a sign. You write things on it.
Harvest drops
Wood× 2
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Wood Debris (Terrain) (75% of the time) where it lands.
Where to find (3 POIs)
Slummit Apartments (tier 2), Hook, Line, & Sinker (tier 1), Poopy Pants Country Daycare (tier 1).
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.