If it was me... i would use opto-coupler instead. For debugging and development, isolated PIC supply, opto-coupler from the main... few meters away of my face always serves me well

If your PIC supply is not isolated of the main, it's another story. If you're using a transformerless PSU (Capacitive dropper) there's few things to know first.

It will help us if you elaborate a little bit more about you app.