If you look at the NickelMenu doc file, there is a sample command called Telnet (toggle). It looks as if you could modify this to start/stop the FTP server as well.
Code:
# menu_item :main :Telnet (toggle) :cmd_output :500:quiet :/usr/bin/pkill -f "^/usr/bin/tcpsvd -E 0.0.0.0 2023"
# chain_success:skip:5
# chain_failure :cmd_spawn :quiet :/bin/mount -t devpts | /bin/grep -q /dev/pts || { /bin/mkdir -p /dev/pts && /bin/mount -t devpts devpts /dev/pts; }
# chain_success :cmd_spawn :quiet :exec /usr/bin/tcpsvd -E 0.0.0.0 2023 /usr/sbin/telnetd -i -l /bin/login
# chain_success :dbg_toast :Started Telnet server on port 2023
# chain_failure :dbg_toast :Error starting Telnet server on port 2023
# chain_always:skip:-1
# chain_success :dbg_toast :Stopped Telnet server on port 2023