Is it possible to run a crypto wallet on a raspberry device? If YES is raspberry PI safe for running crypto wallets? I heard it's just like having a PC in a tiny shape.
It's possible, since it
is a small form-factor PC, so it runs basically any Linux software.
I would probably recommend to use Electrum or Sparrow, but I'm not sure why you'd want to do that.
One reason, as jackg suggested, is if you fear that your main machine is fully virus-infected and don't want to risk getting your coins stolen. Or you may want to run a full node without consuming too much power.
I don't think that in the first situation, storing BTC on a Raspberry Pi is the best solution, though. It has the same attack surface as any other online computer and it will be cumbersome to use, since you'll need to SSH into it every time you make a payment.
For everyday payments, I find hardware wallets to have the best offer in terms of usability and security: you can use them with different devices (at home, at work, with the phone, etc.) and they're more secure than storing
BTC directly on computers and phones.
If you want something for long-term 'HODL' storage, you don't even need a 'wallet' at all. You can create a
Tails USB stick, boot off of it, open Electrum (preinstalled), create a Bitcoin seed and write it on paper or
metal. Also write down a few addresses. Then shut the computer down and you have a fully offline, never-touched-a-live-system seed that you can use in the far future to access any coins sent to those written down addresses.