A B737-300 Captain reported multiple caution lights illuminated on takeoff. Finding no obvious cause; the flight returned to departure airport.

Narrative

Aircraft Master Caution illuminated at approximately 110 knots on takeoff roll. Canceled and continued takeoff. After airborne and safely climbing; discovered 30+ lights from many systems illuminated. Check and cycled light test; master caution recall panel and circuit breakers. Found no obvious reason(s) for lights. Elected to return to [departure airport]; with many lights and concern for shorted wiring made a quick call to Flight Attendants and advised normal return. A short PA was made to the passengers; selected 'RETURN TO FIELD' on ACARS; landed safely; after checklists completed; and taxied to gate. Evaluated declaring an emergency; but weather and traffic not factors; spent ten minutes in air. Called dispatch immediately after gate arrival. Was rudely treated by Dispatcher claiming he had no idea we had returned. The Dispatcher was mad that he had paperwork that he must complete. I later confirmed with [another] Dispatcher that the 'RETURN TO FIELD ' ACARS message from [us] was in fact received when I asked to test the system in coordination with him. Our airline can do better than this. [Maintenance] found shorted Fire Panel that apparently grounded and illuminated a huge number of unrelated lights.