¿Revisamos el botón de emergencia por si acaso?

In a question, present indicative + nosotros can be used to make a suggestion, like Shall we check...?

So ¿Revisamos el botón de emergencia...? means something like:

• Shall we check the emergency button...?
• Do you want us to check the emergency button...?

Revisemos is also possible in some contexts, but it sounds more like a direct proposal or exhortation: Let’s check it.
By contrast, ¿Revisamos...? feels a little softer and more conversational.

Yes, revisamos is formally the present tense of revisar for nosotros.

But in Spanish, the present tense is often used for more than just literal present-time actions. In questions like this, it commonly expresses a suggestion or a near-future action.

So depending on context, revisamos could mean:

• we check
• we are checking
• shall we check
• are we going to check

Here, because it is a question inviting action, the natural interpretation is shall we check?

Spanish often leaves out subject pronouns because the verb ending already tells you who the subject is.

Here, revisamos clearly shows we because of the -amos ending.

So:

• ¿Revisamos el botón de emergencia...?
• ¿Nosotros revisamos el botón de emergencia...?

Both are grammatically possible, but the first one is much more natural unless you want extra emphasis or contrast.

Por si acaso is a very common fixed expression meaning:

• just in case
• in case
• just to be safe

It adds the idea that the action may not be necessary, but it is wise to do it anyway.

So in this sentence, it suggests:

• maybe nothing is wrong,
• but checking the emergency button is a precaution.

It is often used exactly as a set phrase, without needing to analyze each word separately in everyday conversation.

Good question. Both are related, but they are used a little differently.

Por si acaso is a complete fixed phrase meaning just in case.

Por si is often followed by a clause:

• Trae agua por si hace calor. = Bring water in case it gets hot.
• Voy a llamar por si no saben. = I’m going to call in case they don’t know.

In your sentence, por si acaso works by itself at the end, which is very common:

• ¿Revisamos el botón de emergencia por si acaso?

Spanish generally uses articles more often than English.

Here, el botón de emergencia means the emergency button. The article sounds natural because the speaker likely has a specific button in mind: the emergency button in that place, machine, elevator, etc.

Leaving out el here would usually sound incomplete or unnatural.

Spanish often expresses this kind of idea with noun + de + noun.

So:

• botón de emergencia = emergency button
• literally, something like button of emergency

This is a very common Spanish pattern. Other examples:

• sala de espera = waiting room
• tarjeta de crédito = credit card
• cinturón de seguridad = seat belt

So de emergencia is functioning like a descriptive phrase telling you what kind of button it is.

Yes, several verbs could work, but they are not identical in tone or regional usage.

• revisar = to check, inspect, look over
  Very common and widely understood.
• checar = to check
  Very common in much of Latin America, especially Mexico, but more informal.
• verificar = to verify
  Sounds a bit more formal or technical.
• comprobar = to confirm, verify, check
  Also possible, often a bit more formal than revisar.

So ¿Revisamos el botón de emergencia por si acaso? sounds natural, neutral, and widely usable.

Yes. It is very common at the end, but Spanish allows some flexibility.

For example:

• ¿Revisamos el botón de emergencia por si acaso?
• Por si acaso, ¿revisamos el botón de emergencia?

The sentence-final position is probably the most natural here. Putting por si acaso at the beginning gives it a little more emphasis, as if you are framing the whole suggestion as a precaution.

The accent mark shows where the stress goes: bo-TÓN.

Without the accent, Spanish stress rules would make you read it differently. Since botón ends in n, the default stress would normally fall on the second-to-last syllable, but the actual stress is on the last syllable, so the written accent is required.

So:

• botón = correct
• boton = incorrect spelling

It sounds like a polite, practical suggestion.

It is not a strict command. It feels more like:

• Should we check it?
• Want to check it, just in case?
• Maybe we should check it, just to be safe.

So the tone is collaborative and cautious, not forceful.

Usually it sounds more like a preventive or precautionary comment, not something shouted during an active emergency.

If there were a real emergency happening right now, speakers might use something more direct, such as:

• ¡Revisa el botón de emergencia!
• ¡Presiona el botón de emergencia!
• ¡Usa el botón de emergencia!

Your sentence suggests there is time to think and decide: Let’s check it just in case.

Here are some natural variations:

• ¿Revisamos el botón de emergencia por si acaso?
  Neutral, conversational, collaborative.

• Revisemos el botón de emergencia por si acaso.
  More direct: Let’s check the emergency button just in case.

• ¿Podemos revisar el botón de emergencia por si acaso?
  Slightly more polite or cautious: Can we check the emergency button just in case?

• Sería bueno revisar el botón de emergencia por si acaso.
  More indirect: It would be good to check the emergency button, just in case.

All are correct, but your original sentence is very natural in everyday Latin American Spanish.