Detect if mouse is on a player?

Hello. I found through ROBLOX many games where a selectionbox appeared around a character if you had the mouse on the character, and I now need to use that into my game. I made this script....

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()
 
local selection = Instance.new("SelectionBox")
selection.Color3 = Color3.fromRGB(255, 0, 0)
selection.Parent = script
 
mouse.Move:connect(function()
	print ("MouseMoved!")
	local target = mouse.Target
 
	if not target then
		selection.Adornee = nil
	else
		print ("Target is ".. target.Name)
		if target.Parent:IsA("Model") then
			print ("Model!")
			local findhumanoid = target.Parent:FindFirstChild ("Humanoid")
			if findhumanoid ~= nil then
				print ("Humanoid!")
				local findplayer = game.Players:FindFirstChild (findhumanoid.Parent.Name)
				if findplayer ~= nil then
					print ("player!")
					script.SelectedPlayer = findplayer
					selection.Parent = target.Parent
					selection.Adornee = target.Parent
					print ("DONE!")
				end
			end
		end
	end
end)

The script worked fine, with nothing in the output, but, when I held the mouse on a character, no selectionboxes appeared at all. I placed some prints, and I noticed that ROBLOX actually can't detect if the mouse is on a character because the mouse.Target can NOT detect Meshes! I wonder what should I do. What if I create a script that creates a square part on every character and the script, instead of detecting character's meshes, detects the part? Or maybe there is another way? Any help appreciated!