Switzerland· medium
peindre le diable sur la muraille
“to paint the devil on the wall”
Meaning
To imagine the worst possible outcome
Explanation
Used on someone who insists on imagining disaster before anything has actually gone wrong.
Example
Arrête de peindre le diable sur la muraille, l'examen n'est pas si grave que ça.
Stop imagining the worst, the exam isn't that big a deal.
Origin
A near word-for-word copy of the German 'den Teufel an die Wand malen', which carries the same warning: don't summon trouble by dwelling on it.
Source