It has been said before that a crypt wouldn't have electricity or running water. Yet Spike had a fridge for his blood, working tv, he might have taken showers, etc. Hmm... how?
The answer actually is very simple, though often overlooked. There are storage buildings in all cemeteries where
grounds keepers keep their tools and supplies, and it isn't unusual for them to have electricity in order to power lights, power tools, and battery chargers. Also, it isn't uncommon for there to be outdoor power receptacles scattered throughout the grounds for various purposes. Spike could simply find a receptacle in a relatively secluded place, so that it wouldn't likely be discovered, plug in an extension cord, run it to his crypt, and he has electricity. As long as he keeps his consumption low, no one would ever suspect a thing. Another solution would be to run his lights and refrigerator off of 12 volt batteries that he kept charged in his car or paid some garage to do it for him. 12 volt refrigerators are quite common for use in campers and camp trailers, so he could get one easily.
As for water, he could get that from a faucet and a water hose. Once more, his consumption would be limited, but should have been plenty for his purposes.
Now, would anyone like to know why a cave chamber just happened to be conveniently located underneath his crypt? The REAL reason, not just because Joss said that it would be there.