Guard spam is caused by Specific sword Requests
If you're holding an item with a tool head, guard, and grip, that isn't the correctly requested item, The guard requested by the customer will begin to spawn in the middle of the floor under the house, eventually the physics of which will cause it to erupt upwards from the floor.
You can AVOID this by either A) dismissing the Specific Sword requesters right away
OR not getting their order wrong, or not holding the wrong item.
This should hopefully have already been addressed, along with many of the other things I was just talking about in other posts.
Note This gets incredibly harder to avoid if you allow customers to pile up without reloading, as their requests can merge and you'll fail to be capable of even having the chance to notice their presence.
Specific sword requests look like this
blacksmith I need a tin one hand sword with a rare grip, hero guard, and a pointed blade
If you hold a for example
iron, rare grip, hero guard, pointed blade the spam will happen
if you hold a tin common grip hero guard pointed blade
if you hold a tin, rare, normal guard, pointed blade
Even if you hold a spear in which you've added a guard to while completing it, the spam will happen. (at least it did for me while I was testing one of the times)
If you however hold a stolen version, or a non-existent item, The spam will not happen.
Example of a non existent item
A one hand sword blade, on a two hand grip and guard
A dagger with a guard
A pickaxe with a one hand grip
A hatchet with a two hand grip (small axe head)