Home inspectors tend to find more potential problems in an attic than any where else in the home. I don't know of any real estate agent that is willing to go into the attic for you.  This is one reason why you need to hire a home inspector who is a Certified CREIA Inspector or an ASHI Certified Inspector.  
No matter how clean the house inside, the former owner may have added extra electrical in the attic that connects to ceiling fans or lights.  Alot of the time they splice into the wire without the benefit of a junction box. The picture below shows an example of open wire splices (missing a junction box)  found in a condo in Rancho Cucamonga.  THIS IS A POTENTIAL FIRE HAZARD and should be corrected as soon as possible.