I also looked for this fact a long time ago.
Now that I finally found it, I share the address here:
Result by WhatTheFont :
https://image.noelshack.com/fichiers/2019/09/1/1551071582-insidious-font.png
The font has been modified for the film
Modificato su 25/02/2019 alle 06:13 da Axeluuna
Fuso orario: CEST. Ora sono le 17:40