It's #EnigMarch, and when dared to create a puzzle, I do. To find today's hidden message, you will need to cut out a stencil from the key-card. …

It's #EnigMarch, and when dared to create a puzzle, I do. two pieces of graph paper with letters in the squares. one has been labeled 'hidden message'; the other 'key (needs cuts)'

two pieces of graph paper with letters in the squares. one has been labeled 'hidden message'; the other 'key (needs cuts)'

To find today's hidden message, you will need to cut out a stencil from the key-card. Which letters to cut out? The ones that form the cryptic-clued word:

Medium request: a panel with holes cut out (4)

Putting the key-stencil on top of the hidden-message card, making sure all edges coincide, should block the "noise" and let the message (16 characters total) show through. The message: another way to block the noise.

ROT13'd explanation and answer:

Svefg, fbyir gur pelcgvp pyhr. Zrqvhz vf Z. Gb erdhrfg vf gb nfx. Z+NFX znxrf ZNFX.
Va gur xrl-pneq phg bhg gur yrggref N X Z F. Ynl gur xrl-pneq bire gur uvqqra zrffntr pneq. Gurer ner sbhe bevragngvbaf va juvpu gur xrl-pneq'f rqtrf pbvapvqr jvgu gur zrffntr-pneq'f rqtrf. Va rnpu bs gurfr, sbhe yrggref fubhyq fubj guebhtu gur ubyrf va gur xrl pneq.
Gbtrgure, gur fvkgrra yrggref fcryy gur nafjre: FRYRPGVIR URNEVAT