I made a script that creates a selection box when the mouse hovers over a part, but when I do server testing the second client can also see this. I tried placing the code in a LocalScript and it didn't even work at that point.
Not sure if you need the code or if this counts as a request.
But here is my code:
script.Parent.ClickDetector.MouseHoverEnter:connect(function(Player) local sb = Instance.new("SelectionBox") sb.Adornee = script.Parent sb.Parent = script.Parent script.Parent.ClickDetector.MouseHoverLeave:connect(function(Player) sb:Remove() end) end)