Decor and furniture
Sign Canvas Wood 0.75x0.75
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 (4 POIs)
Higashi Pharmaceutical (tier 5), Meat You Here Butchery (tier 3), McPherson UFO Museum (tier 2), Tranquil Terraced Retreat.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.