This guide is for dumping Switch TLS traffic using the Charles web proxy. Please note that this is paid software.
Most Switch communications are over TLS - this includes NEX and Eagle communications (for Nintendo Switch Online)* as well as other servers such as BAAS (friends/status) and NPNS (notifications)
*NPLN, the new Switch online servers that Monster Hunter Rise demo used, cannot be dumped with Charles currently as it doesn't support gRPC - use grpc-dump to dump these communications - the gPRC section will explain this better.
While this doesn't carry much risk in theory, this is risky and could get your Switch banned as you must send your own Switch-unique client certificate.