Builders and archaeologists sometimes comes across old shoes (usually just one of a pair) which have been deliberately hidden in inaccessible places in the fabric of old buildings. Under floorboards, behind bricked-up fireplaces etc etc.

It's not known how or why the practice evolved, but a number of scholars have provided theories about possible reasons.

For an example, see: ‘Revealing the Ritually Concealed: Custodians, Conservators, and the Concealed Shoe’ in Material Religion : The Journal of Objects, Art and Belief, Volume 14, 2018 - Issue 2

“Concealed shoes are footwear purposely concealed within domestic buildings. The motivations behind their concealments are unknown to us, but the prominent theory suggests that shoes were employed as apotropaic (evil-averting) devices.”

Further reading: An open access paper which explores possible reasons why the shoes tend to found one at a time rather than in pairs.

“Drawing on a sample of 100 examples, this paper questions why such shoes were deposited as singles (the present parts), what became of the ‘other shoe’ (the absent part), and how such consideration aids our understanding of this enigmatic custom.”

See : 'The Other Shoe: Fragmentation in the PostMedieval Home' Cambridge Archaeological Journal, Vol. 27 (2): 261-274, December 2016.