With respect to Zarjaz a straight "no" is too definitive. Certainly if a copper line issue is the cause then it is the correct answer.
However, are both you and your neighbour using wireless connectivity for devices? If so, if you are using adjacent wireless channels there can be interference. Devices on the same channel avoid this by negotiation. A few years back the common advice was to scan nearby access points using something like inSSIDer or on a Linux box the "iwlist" command to see what channels nearby access points are using and to try to spread all access points to channels 1, 6 or 11 (or 13) as those do not overlap. See https://en.wikipedia.org/wiki/List_of_WLAN_channels
More modern equipment can use multiple channels though, but the advice still holds, try to gain agreement from those nearby to stick to the channels that do not overlap for optimum performance.
It's unlikely that this is the issue, but it is not beyond the realm of possibility and is good to do from an optimisation point of view.