Yep, I loved flashing lights when I was a kid too. I remember making something like that using Neon tubes (NE2s) and an RC time delay. The thing ran off line voltage. First time I ever plugged it in I had made a wiring mistake on the cap and BANG! nasty explosion - unfortunately I was balancing the whole mess on my leg as I plugged it in. No shock but not pleasant either. Knowing more now I can't believe I didn't kill myself several times over when I was a kid. Like building table radios that ran right off the 2-wire line cord... yikes!