attempt to index nil with 'Hit' on building system hologram/projection script?

im trying to remake a script i made where I could place parts into the map with a tool, for some reason im getting this error on line 35, any help?

--To do, fix this 
local tool = script.Parent
local player = game.Players.LocalPlayer
local character = player.Character
local handle = tool.Handle
local mouse = player:GetMouse()
local currentrotation = 0
local currentparttype = 0
local createdholopart = false

-- functions

local function holo(parttype)
    if not tool:FindFirstChild("HoloPart") then
    print("CreateHoloPart")
    if parttype == 0 then
        local holopart = tool.Assets.WallPartHologram:Clone()
        holopart.Name = "HoloPart"
        holopart.Parent = tool
    else
        if parttype == 1 then

        end
    end
    end


end

local function updholo(mouse)
    print("Updating")
    if tool:FindFirstChild("HoloPart") then
        print("Updated")
        local mouse = mouse
        tool.HoloPart.CFrame = CFrame.new(mouse.Hit.p) -- error is here
        tool.HoloPart.Rotation = Vector3.new(0, currentrotation, 0)
    end
end

-- events
tool.Equipped:Connect(function()
    holo(currentparttype)
    mouse.Idle:Connect(function(mouse)
--yeet  

--local function holo(parttype)
--  if parttype == 0 then
--      local holopart = tool.Assets.WallPartHologram:Clone()
--      holopart.Name = "HoloPart"
--  else
--      if parttype == 1 then
--          
--      end
--  end
--  
--  
--end
--
--local function updholo(mouse)
--  if tool:FindFirstChild("HoloPart") then
--      print("Updated")
--      local mouse = mouse
--      tool.HoloPart.CFrame = CFrame.new(mouse.Hit.p)
--      tool.HoloPart.Rotation = Vector3.new(0, currentrotation, 0)
--  end
--end   

--yeet
        print("Yo")
        if tool:FindFirstChild("HoloPart") then
            print("Sending updator")
            updholo(mouse)
        else
            holo(currentparttype)
        end 


    end)


    mouse.Button1Down:Connect(function(mouse)
        print("Clicked")
        print(mouse.Hit.p)





    end)

    game:GetService("UserInputService").InputBegan:Connect(function(input, gameProcessedEvent)
        if input.KeyCode == Enum.KeyCode.R then
            currentrotation = currentrotation + 45
        else
            if input.KeyCode == Enum.KeyCode.F then
                currentparttype = currentparttype + 1
                if tool:FindFirstChild("HoloPart") then
                    tool.HoloPart:Destroy()
                    holo(currentparttype)
                end 
                if currentparttype > 1 then
                    currentparttype = 0
                end 
            end
        end




    end)
end)