Raycast not facing behind a part?

Hello.

I'm currently trying to make a Raycast detect when an object / part is in the air. My game involves the user being able to place down notes wherever they want if allowed.

Now, there is a way to exploit this by placing the notes on the air, and to combat this I thought using a raycast on the server to check if the part is in the air would be the best solution.

So essentially, my goal is to get a ray to be casted from behind the note so it would hit either a wall, the floor or the roof.

Here's my code so far:

local RayMaximumRange = 2
local RayCastHit = workspace:Raycast(NoteClone.Note.Position, -NoteClone.Note.CFrame.LookVector * RayMaximumRange)

if not (RayCastHit) then
    print("Is in the air ")
end

I'm new to raycasts so I'm actually kind of clueless at the moment.

If I could get some help with this, It'd be great.

Thanks