Do you think we could have a ghost?

we recently moved into a a bungalow and all sorts of things keep happening,pictures have fell off the wall,the tv and radio keep turning themselves on and we have checked for timers on there and there isn't any,we have had loads of lights bulbs we have had to replace because they have blown up and the fire place light turn itself off and on again,i was wondering if maybe it is a ghost of whether you think we need to get our electrics checked by our landlord ,there was a old lady that lived in our house before we did but don't know whether she died or just moved house,the tv and radio turning on always happen in my sons room and in the morning i just want to know whether it is my imaginations or whether there could actually be someone there