A loose neutral wire in the electrical panel can cause you some grief. Make sure you or an electrician look at all your electrical connections in the electrical box or panel. Over years screws can loosen up or wires expand and contract leaving you with a loose connection. Over time the wire/s can start to arc which can cause a light or circuit to dim or fade out all together. Wires can melt leaving you with a potential fire hazard. Save yourself some time, money and headaches by making sure all connections are good and tight.