display turned colorful horizontal lines

[rebeljezebel]

2007 white macbook. very well loved. last night i was listening to music on it while the screen saver was up. i heard the fan get louder and then the screen stopped moving and there were crazy multicolored horizontal lines. the audio continued fine. i turned it off and let it have the night off. seems fine this morning.

any thoughts on what this might be? seems like a red flag ...

 

[l.a.rossmann]

Has it happened again since? Can you catch a picture of it when it does happen again?