Decor and furniture
Sign Decal Wood 4x3
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)
Bob's Boars & Carl's Corn (tier 3), Elite Essentials (tier 2), Warehouse Outpost.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.