Early in designing my 4-inch scale steam-wagon I needed to perform a "sum" a bit too awkward for pen and paper, so turned to my calculator. (This was before I had a computer.)
No calculator. Anywhere.
Oh. Errr. Slide-rule? I had no idea where I'd put that but the gremlins had had plenty to time to disguise and hide it.
Log-tables? Luckily I could find a text-book with the normal maths tables, so could complete the calculation.
Next day I visited Woolworths' where I found that scientific calculators had grown to about half as bulky again as hitherto at the same time as portable 'phones were becoming about two-thirds that of their own predecessors. Gone from shirt-pocket to waxed-jacket pocket size, if you like.
Bought one, and back home, placed it where I would keep seeing it.
A few weeks later I opened a drawer looking for something else entirely, to find the AWOL sum-box, where I knew I had not put it.
I concluded that homes can generate tiny black holes, nowhere near cosmic size but sufficiently larger than the sort the LHC physicists once thought it might make, to be able to absorb small items and render them invisible. However, unable to sustain themselves they soon evaporate, dropping their prey wherever their random wanderings take them.
That's my excuse, anyway…… And it's definitely gremlins hiding things in the workshop.