Ghost in the shop

[Xenomorph]

Anyone figured out how to do this? Walked around after dark with a lamp, swinging with a Tamra weapon all over the place, nothing...

[ImAWall]

I tried the same thing and more - played through the whole game 3-4 times trying to get every achievement and this is the only one I couldn't get. I'd love to know how to unlock it if anyone figured it out

[TrekNx01]

Stuck on this as well,
I have had thoughts it may revolve around the potato or be partially hinted at with the "shovel knight book" but I am yet to figure out the conditions needed.

The only other thought I have had but haven't had any luck with the the lantern colour cycling, it could be that a set pattern or even spectrum is needed.

[SlayerT13]

Trying to figure this out as well, my wife interestingly enough realized you can swap the positions of the potion bottles you can quench with. Maybe something with the position of those bottles could matter? The lantern colors did strike me as odd, but given that you can make basically endless colors on it that seems unlikely to be involved.

[D4rk]

it is so funny to see i'm not the only one swinging such a blade throughout the store xD Anyway do let me know when you guys find it. I've been puzzling with the lights AND the potions as well but so far no luck.
I will post here again if I find it