I don't think there is any way to know if someone visited your facebook account. However you can toggle your ticker by clicking the double arrows. Please see the attached pic for an example.
Please let me know if this gets your ticker back for you.
Hmmm... Just to be clear, that screen shot was taken from my newsfeed. If you don't have a double arrow like that on your newsfeed, then I don't know. I use Windows 7 and have that arrow using Chrome, Firefox, and Internet Explorer. I see you have a Mac and probably use the Safari browser so maybe that's different.
Please double check that you are looking for that arrow on your newsfeed page. If it's still not there, then I will opt out and open this to other experts who might be more familiar with Mac and Safari than I.