How to fix ad inconsistency?

I'm in the home security industry. Basically the first few days I'll get a low cost per lead, let's say $7. Then all of a sudden the ad will spike to $30-40 CPL out of no where and will stay that way. Would anyone have an idea on why this spike is so drastic? I've tested this on multiple audiences, and I'm doing Lead campaigns for website conversions. Thanks in advance.

Facebook is always unstable. You need to test more creative ideas and copywriting, and replace relevant audiences. Facebook advertising is not static.

You can try multiple ways to target a piece of content and create more content to try a few more targets. The sudden increase could be due to a sharp increase in your budget in a short period of time, or it could be due to Facebook, because every day is unusual.