There is a great deal written on the internet about collecting and hording. There seems to be a big difference between the two. Hording can looked up on Google .It says it takes over your life. I do not think any modelers I know come under this condition. I have only known one person who was a hoarder and he had more books than you can emagine. If you can not get around your house because of the clutter you may be a hoarder.
Here is a clip from Google that applies to many of US " When people think of collecting, they may imagine expensive works of art or historical artifacts that are later sold to a museum or listed on eBay. The truth is, for many people who amass collections, the value of their collections are not monetary but emotional —and often, not for sale. Collections allow people to relive their childhoods, to connect themselves to a period in history or to a time they feel strongly about. Their collections may help them to ease insecurity and anxiety about losing a part of themselves, and to keep the past present [1] Some collect for the thrill of the hunt. Collecting is much like a quest, a lifelong pursuit which can never be complete.[2] Collecting may provide psychological security by filling a part of the self one feels is missing or is void of meaning.[3] When one collects, one experiments with arranging, organizing, and presenting a part of the world which may serve to provide a safety zone, a place of refuge where fears are calmed and insecurity is managed.[4] Motives are not mutually exclusive; rather, different motives combine in each collector for a multitude of reasons"
One area that I see a lot is audio speaker hording. Filling the home with speakers,it is very common.
I have no collections at this time but in the past I did get carried away with a small collection of old radios.
Eddyr