[FGZstar] An inspired guess, but NO (but you're by no means up the wrong tree).

[FGZstar] Holds information? NO. * a pedantic throat clearing from one audience member, who is thinking of one specific case *

[CdM] Disparate Things? YES *applause*, altho they do share a couple more properties than just the name.
[Raak] *checks* YES, you can buy at at least two types of this on Amazon.

[Spangle] YES and NO, depending. You could probably argue it either way for quite a few cases. Unlikely to help!
[Raak] Sometimes plastic? YEEES. I did google an example up of a plastic one, but certainly wouldn't have known that if I hadn't.

[Raak] Hardware? I don't recall seeing one in a hardware store. Then again, I can't say I frequent hardware stores.

[Spangle] I'll pick one of the wooden ones, for which the answer is YES, solid wood.

[Raak] Self-made? NO.

[FGzstar] A wedge? NO, but you are absolutely at the right level of generality.

[Raak] Some day my...? NO, but again, the right level of generality

I'm going to be without net access for a week as of late Thurs evening, so perhaps I can do a summary + hints in case it jogs your thoughts. We are looking for the one-word name for a set of mainly functional objects, (at the same level of generality as "chip" or "wedge"). They can be metal or wood. There are a couple other "vegetable" types which are not wood. All of these are typically smaller than a toaster by volume. There is an abstract type too. You could put The Answer into an Amazon search and be offered a couple of types of this. One of the wooden types of this is all wood and has a musical connection. The metal type has a symbolic function.

... apart from the indefinite article, naturally

[Spangle] Vowelish? NO.