The union declared a strike and it appears no-one showed up. So now unions in a completely different industry are going to take action. Sounds like mafia tactics.

Not really. Tesla is reluctant to offer its workers similar rights to others in the country. So the unions are using legitimate tactics to encourage the company to negotiate in good faith. Of course that's somewhat difficult with the current owner in charge.

Members of the union seem to be striking, but the union also pays for them when they strike. Non members don't have to strike, and if they do they're not paid. Sympathy strikes are legal and they've forced many American companies to sign collective agreements. Mafia or not this model works very well for workers in the Nordics.

Please provide sources for that information. That's categorically false and you would not be able to find this information published by a reputable source.

If it were true, there wouldn't be a picket fence and Tesla wouldn't have felt the need to bring in strike breakers.

You're regurgitating lies and misinformation. Please reconsider your sources.

PS. The strike is, as usual in Sweden, incremental and will be expanded every now and then until the pressure is high enough to bring the employer to the table to negotiate in good faith without causing unnecessary harm to the company (and, consequently, its labour). If you think this current and partial strike is all that's going to happen if Tesla refuse to actually negotiate, then you're in for a big surprise my friend.