Zenith26kc20 makes a good point...those early SS monster amps can cause many fires...one way they did it was to 'go DC' and set the woofers in the loudspeakers ablaze....NOT good! Thinking of Hafler, Phase Linear, Sansui, and others.
I make a point of never leaving my tube gear on when I'm out, but I have done it (modern hifi amp mostly, a Rogue Audio integrated EL34) but then again i retrofitted the stereo cabinet to have a 12v computer fan whenever the amp is lit... and the thing has 6 fuses total...one per output tube, a b pos fuse and a main fuse.
As far as the tv's, i never leave em on since my grandma used to tell a story of their tv going on fire as my grandpa was asleep in front of it one time..."hey why the hell are you making toast in the middle of the night?!" ---
It was an un-identified early 70s color set...probably a hybrid