I have noticed that the 's' is often exchanged with a 'z' in the word paradise!

The word paradise does not contain the suffix -ise. It is ultimately from and Old Iranian word pari- 'around' (cf. Greek περι- (peri-) + daiz- 'to heap up, build' (cf. English dough, Latin fingō 'to touch, handle; form, shape') meaning enclosure and later walled park or garden.

Ceci n'est pas un seing.