Use a non thematic site for guest post : a good idea ?

Hi, I have an opportunity for guestposts on good sites with traffic but two problems remain :

- Some of them re not in my niche (ex : sport, when my niche are financials)
- Some of them are not in my language (english while my one is french)

I was thinking about :
- Write an article which ll link the both thematics
- When language is different maybe try a guest post in french (or maybe fr + english version ?)

Thanks for your advices

If topic is different, you still can build a good guest post link. Just write an article that will perfectly fit an editorial policy, but add a paragraph or two which would create a good contextual opportunity too link out to a site you own.

Same thing with another language - writing just in French would be enough. BTW you can write English translation and publish it on your internal blog. This would be a good reason to build an extra link to it.

Both of these links will work great as exclusion (if you have at least 20 guest posts from relevant sites and diversified backlink profile, etc)

If guest posting sites allow completely different niche and completely different language, then they are quite probably guest post farms and I would avoid such sites. Due diligence is in order here.