In the ISE, type:
Get-Command -Module IS<CTRL-SPACE>
Wait a second or so for the tooltip to appear.  You'll see:
Description:
ModuleType: Script
Path: C:\Windows\System32\WindowsPowerShell\v1.0\Modules\ISE\ISE.psm1

The same sort of tooltip appears when you type:
Get-Module -Name IS<CTRL-SPACE>