Electrical current, zapping

Not so much for the “kkzzr” but more for the “crkck”, try sticking various long strands of industrial strength packing tape to a firmly mounted window, and experiment with pulling it off in a way that causes a krk-krk-krk-krk stuttering effect. (The window amplifies the effect nicely).
– Paul Gorman

1. high-pass a noise generator @ 8K and attach a random LFO to amplitude. 2. high-pass a recording of sizzling bacon. 3. record the sound of shooting a spray gun at a hot iron for sizzle fx. 4. sequence random splotches of high-passed turntable scratches. 5. twist up cellophane and high pass it. 6. scratch up nylon material and record it close mic’d. eq to taste.
– Jamey Scott

Processing styrofoam creaks and crunches.
– Charles Deenen

Do you have an Ionic Breeze or equivalent air purifier? Try letting it go for 4-6 weeks without cleaning, and you’ll start getting some really nasty arcing from all the dust accumulation on the plates and wires. If you have a high-res mic (50k freq-response) and a 96k recorder, you can pitch it down an octave or 2 for some really big arcs and zaps.
– Chris Clanin

Try (squeezing) some steel wool. Also you can try steel wool soaked in some salt water… Just a little.
– Coll Anderson

Whip a porcelain sink or bath tub with a small metal chain (like the one attached to the sink plug). Then add distortion to the recording.
– David Filskov

Train wheels on track.
– Paul Arnold

BE *VERY* CAREFUL WITH THESE!

Electrical hum / buzzing effect can be created with an electric condenser where the diaphragm has been removed exposing the FET.
– Mike Rooke

If you take the hot lead of a line (or mic) in (bare wire works best but tip of a 1/4″ works also) and touch it lightly to various metal surfaces you can get some great arc sounds. Of course they are completely dry so you should put some reverb on them.
– Scott Koué

Electric welding works well too.
– Manuel Laval

If you need some sounds to work from, you can give Dave Fienup’s Sci-Fi electric library a try.