i810switch: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/i810switch - from package: i810switch

You may install the required package with command apt-get install {package}
Error in other languages:
i810switch: bevel nie gevind nie
i810switch: comandă negăsită
i810switch: comando não encontrado
i810switch: commande introuvable
i810switch: command not found
i810switch: käsku ei ole
i810switch: không tìm thấy lệnh
i810switch: komanda nerasta
i810switch: Kommando nicht gefunden.
i810switch: kommandot finns inte
i810switch: komut yok
i810switch: nie znaleziono polecenia
i810switch: níor aimsíodh an t-ordú
i810switch: no se encontró la orden
i810switch: no s'ha trobat l'ordre
i810switch: opdracht niet gevonden
i810switch: parancs nem található
i810switch: perintah tidak ditemukan
i810switch: príkaz nenájdený
i810switch: příkaz nenalezen
i810switch: команда не найдена
i810switch: командата не е открита
i810switch: 命令找不到
i810switch: コマンドが見つかりません