I never thought of cut adpaptor to use hold bulb. I guess it's good idea.
but my problem is not bulb secure issue. Bulb is secure and tight.
I'm more interest on 470uF 25V capacitor.
I had kind of same ploblem bouncing light but not couse by bulb move.
Mine is tight and secure. light does not brink but it move up & down
like bulb is moving.
I thought it was voltage ploblem so I purchase
Relay but it didn't work either.
Still try to find out what to cause but most...