Red light running fine script doesn't subtract $300 from the player's $$$ leaderstat?

#Local Scripts The point of local scripts is to make edits to something only a client can see. UI or local parts can only be seen by a single client, so those are edited via local scripts. If you're making changes to the game, you need to use a server sided (or normal)

#How to Get Player with a Server Script Use GetPlayerFromCharacter. The argument is the player's character and it will return the character.

local Players = game:GetService("Players")

local player = Players:GetPlayerFromCharacter(Character) --"Character" will be the model
if player then --If the player is real then...
	print(player.Name.." is a player.")
else --If the player is not real then...
	print("Not a player...")
end

#Implementing with a Touched event Here's how your code would look like if you combined it with GetPlayerFromCharacter.

local Part = script.Parent
Part.Touched:Connect(function(hit)
	local player = game:GetService("Players"):GetPlayerFromCharacter(hit.Parent)
	if player and script.Parent.Parent.TrafficLight1.TSM.Red.PointLight.Brightness == 8 then
		player.leaderstats.Money.Value = player.leaderstats.Money.Value - 300
	end
end)

#Debouncing If you were to use the code as is, you'd notice that you are losing a lot more cash than just 300. The reason is because this code is being run once for every single body part and cosmetic the player is wearing. Meaning, if a player is wearing 3 hats, he could lose up to $2,700 at once! If you put a debounce, it will prevent the code from running again until a certain condition is met. In this example, the condition is time:

--Button can only be pressed once every 5 seconds
local debounce = false --can be named anything; variable doesn't have to be a bool, it's just easier that way

script.Parent.Touched:Connect(function()
	if not debounce then --If debounce is false then...
		debounce = true --Make it true, so this script wont run again!
		print("Activated")
		wait(5) --After 5 seconds, make debounce false again
		debounce = false --Now the script is ready to be pressed again
	end
end)

#Final Product

local Part = script.Parent
local debounce = false

Part.Touched:Connect(function(hit)
	local player = game:GetService("Players"):GetPlayerFromCharacter(hit.Parent)
	if not debounce and player and script.Parent.Parent.TrafficLight1.TSM.Red.PointLight.Brightness == 8 then
		debounce = true
		player.leaderstats.Money.Value = player.leaderstats.Money.Value - 300
		wait(1.5) --or however long it takes for the player to cross the red light in seconds
		debounce = false
	end
end)

Hope it helps!