How can construction ghosts be removed?

[LegionMammal978]

Question in the title. Accidentally shift-clicked a stack of shone bricks instead of ctrl-clicking it, and now I have to get rid of all the ghosts.

[DaveMcW]

Deconstruct the entire area. This removes ghosts and marks building for deconstruction.
Shift+Deconstruct the entire area. This unmarks buildings.

[Greybeard_LXI]

If you do not have blue prints yet, you can right click and drag over the ghosts. They take no time to remove.

[Engimage]

If you do not have blue prints yet, you can right click and drag over the ghosts. They take no time to remove.

If he has no blueprints than ghosts can be created only by destroying stuff (biters or friendly fire). In this case ghosts will disappear shortly by their own. Only player placed ghosts last forever.
And any ghosts can be removed by "deconstructing" them by either deconstruction planner or right-click-holding (mining) them.

[Greybeard_LXI]

Even without blue prints if you hold something in your hand and shift + click it will place a ghost.

I used it to help lay out my first bus. I was real surprised that I got messages about missing parts when a new roboport construction zone included the extension of my bus.