Electrical System gone haywire

We have a '21Tag Boondock parked at our house that we've been sleeping in the past couple weeks while our house is being worked on.  It has not been plugged in, just relying on solar.  We left for a week and came back to find all kinds of electrical problems.
I first noticed the reading light began flickering intermittently.  Then, when I plugged in my phone to charge the reading light turned into a full on strobe.  When I turn on the ceiling fan, the reading lights go out completely. The interior roof lights, outside lights, and stereo have shut down completely.
Any ideas?