switcher: command not found

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 CentOS possible default full paths are:

/usr/bin/switcher - from package: boinc-client

You may install the required package with command yum install {package}

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