Now... at what point does a collection become a mania, a dangerous hoarding problem?

Pyrex Love FAQ
But back to the hoarding question; I don't have room for everything in my cupboards or even in the Hoosier cabinet, so there are always stray bits of my collection on counters or the kitchen table. Linens, too... my linen closet door won't close.
I'll admit right here that I can't watch those hoarding shows (like 'Hoarding; Buried Alive' on TLC) because it gives me the icks. But that's because the places are always filthy, and I get itchy just thinking about it. I'm not the best housekeeper in the world, but I have my limits.
So... hoarder or collector? You'll be happy to know TLC's site has a quiz about hoarding, (click here) though it doesn't really answer the 'hoarder or collector' question. Based on most of the factors though, I am just a collector whose collection is a leeetle too big for my available space. That's my story, and I'm sticking to it.
My second reason for an interest in it is that I am using a hoarder as a character in Book Two, Bowled Over. Jaymie has been accused of hoarding by nitpicky-neat sister Becca, and is questioning her own love of 'stuff', but when she comes across a true case of it, she knows she's not a hoarder. Not yet, anyway! LOL.
Seriously, though, true hoarding is a psychological condition that can become dangerous if the house is so congested that the person who lives there can't move around, is in danger of tripping, or if the place is dirty. Have you ever seen a place like that?