One thing that always intrigues me about Spain is the Catholic iconography. In many of the older, traditional apartment blocks here in Madrid, they have ex-votos pinned on the front doors of the flats. Ours has one too, from a previous owner, and somewhat worse for wear, but then it is 100 years old! After searching the internet (Google knows everything), I found an identical version listed on Etsy, in considerably better condition, selling for 100 euros. Apparently it comes from France, which explains why it says 'Montmartre' I suppose.
On the subject of Etsy, I have just started my own Etsy shop too, and although I won't be selling the ex-voto (unless I get desperate) I will use this opportunity to shamelessly promote it. Click the link if you fancy buying prints of my drawings!