Heres my code... I tried editing it, but then it ends up not working.
wait(0.1)
local player = game.Players.LocalPlayer
local mouse = player:GetMouse()
local blankPart = game.Players.LocalPlayer.PlayerGui.BlockGui.Block.Part
blankPart.Anchored=true
blankPart.CanCollide=false
blankPart.Transparency=0.75
while true do
wait(0.2)
local part = blankPart:Clone() --never change the original part, only a clone
part.Parent=workspace
mouse.TargetFilter=part --ignore the clone while getting mouse position
local p = mouse.Hit.p
part.Position = Vector3.new(math.floor(p.X),math.ceil(p.Y),math.floor(p.Z)) --mouse position in whole numbers
mouse.Button1Down:wait() --do not have to connect a click function :)
part.CanCollide=true
part.Transparency=0
end

1 comment
Can show show me what I would use?