How do I define nothigness in player's backpack?

So basically, I've made a script that checks for contraband after the player walks over a certain part. If found any contraband it triggers an alarm and a light turns red. If it found tools in player's backpack but none are named like the contrabands the light turns green and then yellow. If the player doesn't have any tools the light will remain yellow. How to make it so the light turns green even if the player has no tools? I was trying to use nil value but it didn't work for me.

local contraband = {
    "AK74M", 
    "USP",
}
local players = game:GetService("Players")

script.Parent.Touched:Connect(function(hit)
    local player = players:GetPlayerFromCharacter(hit.Parent)
    for i,v in pairs(player.Backpack:GetChildren()) do
        if table.find(contraband,v.Name) and script.Parent.Parent.Light.Sound.Playing == false then
            script.Parent.Parent.Light.BrickColor = BrickColor.new("Bright red")
            script.Parent.Parent.Light.Sound:Play()
        elseif not table.find(contraband,v.Name) and script.Parent.Parent.Light.Sound.Playing == false then
            script.Parent.Parent.Light.BrickColor = BrickColor.new("Lime green")
            wait(1)
            script.Parent.Parent.Light.BrickColor = BrickColor.new("Neon orange")
        end
    end
end)